Participation and population by state and school year

What this dataset measures

Built to test whether girls' high school sports participation fell in states after they passed laws like Washington Initiative IL26-638. NFHS is the only national source of participation by state and sex; Census estimates give per-capita denominators.

Geography

United States, 50 states and the District of Columbia

Unit of observation

State (or DC) by school year

Update cadence

Annual, after each NFHS survey (usually August)

Curator

FactHub Research Team

Curated data tables

Participation and population by state and school year

NFHS boys and girls participants, Census population aged 14-17 by sex, law group, and derived rates.

Unit of observation: State by school year

state-year-participation.csv text/csv · 37.5 KB (38,398 bytes)

The first 100 of 459 rows 15 columns Download the full file

The first 100 of 459 rows

state	schoolYear	group	lawFirstYear	girls participation entries	boys participation entries	totalReported participation entries	girlsPop14to17 persons	boysPop14to17 persons	girlsPer1000 participants per 1,000 girls aged 14-17	boysPer1000 participants per 1,000 boys aged 14-17	girlsSharePct percent	girlsFlagFootball participation entries	girlsWrestling participation entries	girlsExFlagWrestlingPer1000 participants per 1,000 girls aged 14-17
Alabama	2015-16	law	2021-22	44811	84886	129697	126975	131847	352.9	643.8	34.55	—	—	—
Alabama	2016-17	law	2021-22	46801	86568	133369	126056	130347	371.3	664.1	35.09	—	—	—
Alabama	2017-18	law	2021-22	47616	88374	135990	124613	128894	382.1	685.6	35.01	—	—	—
Alabama	2018-19	law	2021-22	49001	89714	138715	122726	127084	399.3	705.9	35.32	0	0	399.3
Alabama	2021-22	law	2021-22	51355	90110	141465	127286	133381	403.5	675.6	36.3	—	—	—
Alabama	2022-23	law	2021-22	70021	109519	179540	129151	135056	542.2	810.9	39	—	—	—
Alabama	2023-24	law	2021-22	69407	104720	174127	130268	136345	532.8	768.1	39.86	—	—	—
Alabama	2024-25	law	2021-22	65489	106843	172332	131002	136933	499.9	780.3	38	1596	916	480.7
Alabama	2025-26	law	2021-22	73808	121961	195769	129333	135575	570.7	899.6	37.7	3372	1150	535.7
Alaska	2015-16	policy	—	9516	12024	21540	19161	20491	496.6	586.8	44.18	—	—	—
Alaska	2016-17	policy	—	9524	11641	21165	19148	20438	497.4	569.6	45	—	—	—
Alaska	2017-18	policy	—	10647	11998	22645	19018	20070	559.8	597.8	47.02	—	—	—
Alaska	2018-19	policy	—	10129	11345	21474	18741	19576	540.5	579.5	47.17	475	347	496.6
Alaska	2021-22	policy	—	7660	8802	16462	18709	20245	409.4	434.8	46.53	—	—	—
Alaska	2022-23	policy	—	6959	8481	15440	18824	20497	369.7	413.8	45.07	—	—	—
Alaska	2023-24	policy	—	9184	9656	18840	18861	20776	486.9	464.8	48.75	—	—	—
Alaska	2024-25	policy	—	8341	10134	18475	19147	20833	435.6	486.4	45.15	416	621	381.5
Alaska	2025-26	policy	—	11097	9885	20982	19142	20745	579.7	476.5	52.89	470	507	528.7
Arizona	2015-16	law	2022-23	51876	71198	123074	180866	188058	286.8	378.6	42.15	—	—	—
Arizona	2016-17	law	2022-23	52550	71080	123630	182115	188627	288.6	376.8	42.51	—	—	—
Arizona	2017-18	law	2022-23	51983	69335	121318	182270	188956	285.2	366.9	42.85	—	—	—
Arizona	2018-19	law	2022-23	52817	68520	121337	182527	189630	289.4	361.3	43.53	0	481	286.7
Arizona	2021-22	law	2022-23	51702	68931	120633	191083	200511	270.6	343.8	42.86	—	—	—
Arizona	2022-23	law	2022-23	54889	75379	130268	193980	202994	283	371.3	42.14	—	—	—
Arizona	2023-24	law	2022-23	57242	75794	133036	194545	203525	294.2	372.4	43.03	—	—	—
Arizona	2024-25	law	2022-23	59392	77393	136785	193768	202860	306.5	381.5	43.42	3003	1677	282.4
Arizona	2025-26	law	2022-23	60950	77852	138802	190408	199386	320.1	390.5	43.91	3999	1843	289.4
Arkansas	2015-16	law	2021-22	24625	38477	63102	77933	81925	316	469.7	39.02	—	—	—
Arkansas	2016-17	law	2021-22	27045	39410	66455	77875	81473	347.3	483.7	40.7	—	—	—
Arkansas	2017-18	law	2021-22	28186	39818	68004	77469	81578	363.8	488.1	41.45	—	—	—
Arkansas	2018-19	law	2021-22	26296	42976	69272	77070	81198	341.2	529.3	37.96	0	54	340.5
Arkansas	2021-22	law	2021-22	25694	34786	60480	80345	84333	319.8	412.5	42.48	—	—	—
Arkansas	2022-23	law	2021-22	34627	46587	81214	81809	85777	423.3	543.1	42.64	—	—	—
Arkansas	2023-24	law	2021-22	40337	52341	92678	82429	85990	489.4	608.7	43.52	—	—	—
Arkansas	2024-25	law	2021-22	36867	51511	88378	82309	86189	447.9	597.7	41.72	18	683	439.4
Arkansas	2025-26	law	2021-22	35139	48810	83949	81194	85168	432.8	573.1	41.86	0	845	422.4
California	2015-16	noLaw	—	338980	463137	802117	1006609	1051742	336.8	440.4	42.26	—	—	—
California	2016-17	noLaw	—	337851	462513	800364	997627	1041759	338.7	444	42.21	—	—	—
California	2017-18	noLaw	—	353850	465775	819625	994088	1036384	356	449.4	43.17	—	—	—
California	2018-19	noLaw	—	358920	465789	824709	987614	1027236	363.4	453.4	43.52	660	6014	356.7
California	2021-22	noLaw	—	328588	434235	762823	1014654	1064727	323.8	407.8	43.08	—	—	—
California	2022-23	noLaw	—	337266	450431	787697	1017277	1066231	331.5	422.5	42.82	—	—	—
California	2023-24	noLaw	—	363610	470493	834103	1010835	1058852	359.7	444.3	43.59	—	—	—
California	2024-25	noLaw	—	377699	474876	852575	1000341	1048636	377.6	452.9	44.3	19921	8831	348.8
California	2025-26	noLaw	—	384813	474209	859022	977380	1023333	393.7	463.4	44.8	24979	10204	357.7
Colorado	2015-16	noLaw	—	59654	74363	134017	136013	142200	438.6	522.9	44.51	—	—	—
Colorado	2016-17	noLaw	—	60737	74477	135214	137781	144215	440.8	516.4	44.92	—	—	—
Colorado	2017-18	noLaw	—	59525	72901	132426	139446	146115	426.9	498.9	44.95	—	—	—
Colorado	2018-19	noLaw	—	61830	75952	137782	141084	147277	438.2	515.7	44.88	0	140	437.3
Colorado	2021-22	noLaw	—	66100	79171	145271	146359	154675	451.6	511.9	45.5	—	—	—
Colorado	2022-23	noLaw	—	75342	77127	152469	146304	154722	515	498.5	49.41	—	—	—
Colorado	2023-24	noLaw	—	58807	77579	136386	145962	154379	402.9	502.5	43.12	—	—	—
Colorado	2024-25	noLaw	—	66589	80550	147139	145186	154545	458.6	521.2	45.26	1972	1326	435.9
Colorado	2025-26	noLaw	—	63232	77766	140998	142711	151863	443.1	512.1	44.85	2447	1751	413.7
Connecticut	2015-16	noLaw	—	51028	61178	112206	93090	97878	548.2	625	45.48	—	—	—
Connecticut	2016-17	noLaw	—	50350	60167	110517	91863	96657	548.1	622.5	45.56	—	—	—
Connecticut	2017-18	noLaw	—	51911	59217	111128	90554	94972	573.3	623.5	46.71	—	—	—
Connecticut	2018-19	noLaw	—	49563	58624	108187	89482	93816	553.9	624.9	45.81	0	131	552.4
Connecticut	2021-22	noLaw	—	43231	54706	97937	90384	94245	478.3	580.5	44.14	—	—	—
Connecticut	2022-23	noLaw	—	48012	60215	108227	90022	93514	533.3	643.9	44.36	—	—	—
Connecticut	2023-24	noLaw	—	48012	60215	108227	89182	92868	538.4	648.4	44.36	—	—	—
Connecticut	2024-25	noLaw	—	48338	63326	111664	88636	92245	545.4	686.5	43.29	0	357	541.3
Connecticut	2025-26	noLaw	—	47387	59666	107053	87169	90333	543.6	660.5	44.26	0	449	538.5
Delaware	2015-16	noLaw	—	12567	15781	28348	22728	23750	552.9	664.5	44.33	—	—	—
Delaware	2016-17	noLaw	—	13078	16488	29566	22686	23624	576.5	697.9	44.23	—	—	—
Delaware	2017-18	noLaw	—	13139	16902	30041	22799	23789	576.3	710.5	43.74	—	—	—
Delaware	2018-19	noLaw	—	12099	15980	28079	22710	23669	532.8	675.1	43.09	0	11	532.3
Delaware	2021-22	noLaw	—	11170	14795	25965	24652	25194	453.1	587.2	43.02	—	—	—
Delaware	2022-23	noLaw	—	11170	14795	25965	24870	25417	449.1	582.1	43.02	—	—	—
Delaware	2023-24	noLaw	—	11170	14795	25965	25159	25930	444	570.6	43.02	—	—	—
Delaware	2024-25	noLaw	—	11571	16341	27912	25115	25926	460.7	630.3	41.46	0	86	457.3
Delaware	2025-26	noLaw	—	11825	16089	27914	24813	25686	476.6	626.4	42.36	183	291	457.5
District of Columbia	2015-16	noLaw	—	5006	7343	12349	10352	10685	483.6	687.2	40.54	—	—	—
District of Columbia	2016-17	noLaw	—	5377	7580	12957	10333	10537	520.4	719.4	41.5	—	—	—
District of Columbia	2017-18	noLaw	—	5203	7623	12826	10307	10541	504.8	723.2	40.57	—	—	—
District of Columbia	2018-19	noLaw	—	6088	8492	14580	10353	10408	588	815.9	41.76	221	7	566
District of Columbia	2021-22	noLaw	—	1176	1893	3069	10268	10382	114.5	182.3	38.32	—	—	—
District of Columbia	2022-23	noLaw	—	1176	1893	3069	10720	10701	109.7	176.9	38.32	—	—	—
District of Columbia	2023-24	noLaw	—	6062	7252	13314	11001	11310	551	641.2	45.53	—	—	—
District of Columbia	2024-25	noLaw	—	6062	7252	13314	11309	11546	536	628.1	45.53	235	24	513.1
District of Columbia	2025-26	noLaw	—	6635	8925	15560	11462	11699	578.9	762.9	42.64	240	30	555.3
Florida	2015-16	law	2021-22	123220	162665	285885	467828	486918	263.4	334.1	43.1	—	—	—
Florida	2016-17	law	2021-22	134522	176045	310567	471046	490081	285.6	359.2	43.31	—	—	—
Florida	2017-18	law	2021-22	136136	175225	311361	470938	489618	289.1	357.9	43.72	—	—	—
Florida	2018-19	law	2021-22	134518	173655	308173	470118	488347	286.1	355.6	43.65	7683	475	268.8
Florida	2021-22	law	2021-22	129128	162376	291504	500177	523053	258.2	310.4	44.3	—	—	—
Florida	2022-23	law	2021-22	130989	166400	297389	515984	540034	253.9	308.1	44.05	—	—	—
Florida	2023-24	law	2021-22	131216	168182	299398	524972	549254	249.9	306.2	43.83	—	—	—
Florida	2024-25	law	2021-22	136354	172042	308396	525915	550318	259.3	312.6	44.21	10924	2130	234.4
Florida	2025-26	law	2021-22	136857	174376	311233	519958	543545	263.2	320.8	43.97	12424	2328	234.8
Georgia	2015-16	law	2022-23	79746	120510	200256	280724	291392	284.1	413.6	39.82	—	—	—
Georgia	2016-17	law	2022-23	81523	121213	202736	283725	294324	287.3	411.8	40.21	—	—	—
Georgia	2017-18	law	2022-23	80480	120987	201467	285892	294710	281.5	410.5	39.95	—	—	—
Georgia	2018-19	law	2022-23	76666	118736	195402	285657	293421	268.4	404.7	39.24	0	427	266.9
Georgia	2021-22	law	2022-23	77708	113140	190848	296723	309212	261.9	365.9	40.72	—	—	—
Georgia	2022-23	law	2022-23	80897	119451	200348	300531	313823	269.2	380.6	40.38	—	—	—
Georgia	2023-24	law	2022-23	86548	124827	211375	302389	315714	286.2	395.4	40.95	—	—	—
Georgia	2024-25	law	2022-23	87541	123636	211177	302867	315747	289	391.6	41.45	7084	2095	258.7
Georgia	2025-26	law	2022-23	94470	129271	223741	298432	311238	316.6	415.3	42.22	8320	2472	280.4
Hawaii	2015-16	noLaw	—	15480	20588	36068	31257	32602	495.2	631.5	42.92	—	—	—

15 field definitions

Field	Type	Meaning	Units	Value type
state	string	State name or District of Columbia	—	observed
schoolYear	string	School year, such as 2018-19	—	observed
group	string	law (one of the 27 law states), noLaw (no statewide law or policy), or policy (Alaska, Virginia: state policy, not law)	—	derived
lawFirstYear	string	First school year counted as covered by the state law	—	derived
girls	integer	Girls participants, Totals by State table	participation entries	observed
boys	integer	Boys participants, Totals by State table	participation entries	observed
totalReported	integer	Total as printed by NFHS (equals boys + girls except North Dakota 2021-22, +90, and Kansas 2024-25, +1)	participation entries	observed
girlsPop14to17	integer	Civilian female population aged 14-17 on July 1 of the school year's first calendar year	persons	estimated
boysPop14to17	integer	Civilian male population aged 14-17, same basis	persons	estimated
girlsPer1000	number	1,000 x girls / girlsPop14to17	participants per 1,000 girls aged 14-17	derived
boysPer1000	number	1,000 x boys / boysPop14to17	participants per 1,000 boys aged 14-17	derived
girlsSharePct	number	Girls as a share of boys + girls participants	percent	derived
girlsFlagFootball	integer	Girls' flag football participants (2018-19, 2024-25, 2025-26 only; 0 where the state reported none; empty in other years)	participation entries	observed
girlsWrestling	integer	Girls' wrestling participants (2018-19, 2024-25, 2025-26 only; empty in other years)	participation entries	observed
girlsExFlagWrestlingPer1000	number	Girls per 1,000 excluding flag football and wrestling (empty in other years)	participants per 1,000 girls aged 14-17	derived

Supporting files

Source snapshots, manifests, quality reports, documentation, and other materials used to produce or review this release.

• parse.js Transformation manifest · text/javascript · 1.3 KB (1,350 bytes)

  Reads the Totals by State table from each NFHS survey (pdftotext -raw output).

• sport.js Transformation manifest · text/javascript · 1.8 KB (1,829 bytes)

  Reads one girls' sport column by state from the NFHS survey (pdftotext -table output); used for wrestling and 2025-26 flag football.

• analyze.js Transformation manifest · text/javascript · 4.4 KB (4,464 bytes)

  Joins NFHS totals, law groups and Census population into the state-year panel and computes group series.

• analyze2.js Transformation manifest · text/javascript · 6.6 KB (6,735 bytes)

  Computes every difference-in-differences estimate, robustness check and table in this dataset.

• build-csv.js Transformation manifest · text/javascript · 1.1 KB (1,139 bytes)

  Writes the two CSV tables from the computed panel.

• laws.json Transformation manifest · application/json · 2.9 KB (2,984 bytes)

  Law list used by the scripts (same content as state-laws.csv).

• f2425.json Transformation manifest · application/json · 328 bytes

  Girls' flag football by state, 2024-25, transcribed from the NFHS other-sports list; sums to the national 68,847.

• f1819.json Transformation manifest · application/json · 112 bytes

  Girls' flag football by state, 2018-19, transcribed from the NFHS other-sports list; sums to the national 11,209.

• README.md Documentation · text/markdown · 1.8 KB (1,823 bytes)

  How to reproduce the tables and analyses from the NFHS and Census files.

• dataset-parts.json Documentation · application/json · 62.1 KB (63,603 bytes)

  Machine-readable copy of version 1 sources, tables, events and saved analyses (version 2 adds four analyses and two sources, listed in the changelog).

• v2-checks.js Transformation manifest · text/javascript · 4.9 KB (5,027 bytes)

  Computes the catch-up regression, the timing table and the universal-verification comparison added in version 2.

Sources

1. NFHS High School Athletics Participation Survey, 2015-16 Participation counts by state and sex (Totals by State table) for 2015-16

   Retrieved October 23, 2026. NFHS copyright; factual figures used with attribution. Derived state totals republished with attribution; the PDF itself is linked, not hosted.

   Reliability: Other. The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws.

2. NFHS High School Athletics Participation Survey, 2016-17 Participation counts by state and sex (Totals by State table) for 2016-17

   Retrieved October 23, 2026. NFHS copyright; factual figures used with attribution. Derived state totals republished with attribution; the PDF itself is linked, not hosted.

   Reliability: Other. The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws.

3. NFHS High School Athletics Participation Survey, 2017-18 Participation counts by state and sex (Totals by State table) for 2017-18

   Retrieved October 23, 2026. NFHS copyright; factual figures used with attribution. Derived state totals republished with attribution; the PDF itself is linked, not hosted.

   Reliability: Other. The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws.

4. NFHS High School Athletics Participation Survey, 2018-19 Participation counts by state and sex (Totals by State table) for 2018-19, plus girls' wrestling and flag football by state

   Retrieved October 23, 2026. NFHS copyright; factual figures used with attribution. Derived state totals republished with attribution; the PDF itself is linked, not hosted.

   Reliability: Other. The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws.

5. NFHS High School Athletics Participation Survey, 2021-22 Participation counts by state and sex (Totals by State table) for 2021-22

   Retrieved October 23, 2026. NFHS copyright; factual figures used with attribution. Derived state totals republished with attribution; the PDF itself is linked, not hosted.

   Reliability: Other. The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws.

6. NFHS High School Athletics Participation Survey, 2022-23 Participation counts by state and sex (Totals by State table) for 2022-23

   Retrieved October 23, 2026. NFHS copyright; factual figures used with attribution. Derived state totals republished with attribution; the PDF itself is linked, not hosted.

   Reliability: Other. The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws.

7. NFHS High School Athletics Participation Survey, 2023-24 Participation counts by state and sex (Totals by State table) for 2023-24

   Retrieved October 23, 2026. NFHS copyright; factual figures used with attribution. Derived state totals republished with attribution; the PDF itself is linked, not hosted.

   Reliability: Other. The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws.

8. NFHS High School Athletics Participation Survey, 2024-25 Participation counts by state and sex (Totals by State table) for 2024-25, plus girls' wrestling and flag football by state

   Retrieved October 23, 2026. NFHS copyright; factual figures used with attribution. Derived state totals republished with attribution; the PDF itself is linked, not hosted.

   Reliability: Other. The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws.

9. NFHS High School Athletics Participation Survey, 2025-26 Participation counts by state and sex (Totals by State table) for 2025-26, plus girls' wrestling and flag football by state

   Retrieved October 23, 2026. NFHS copyright; factual figures used with attribution. Derived state totals republished with attribution; the PDF itself is linked, not hosted.

   Reliability: Other. The National Federation of State High School Associations compiles counts reported by its 51 member state associations. A student in two sports counts twice. The survey takes no position on state eligibility laws.

10. NFHS news release (August 2026): Led by Girls Flag Football and Girls Wrestling, High School Sports Participation Increases for Fifth Consecutive Year National 2025-26 totals and the growth of girls' flag football and wrestling

    Retrieved October 23, 2026. NFHS copyright; quoted with attribution. Linked, not hosted.

    Reliability: Other. Has a stake in this finding. NFHS promotes high school sports and reports on its own survey; its framing of growth is promotional, but the figures match the survey tables.

11. U.S. Census Bureau, Annual Estimates of the Civilian Population by Single Year of Age and Sex for States, 2010-2019 (SC-EST2019-AGESEX-CIV) July 1, 2015-2018 civilian population ages 14-17 by sex and state (denominators for 2015-16 to 2018-19) Free copy

    Retrieved October 23, 2026. Public domain (U.S. government work). Aggregates republished.

    Reliability: Government. Census Bureau population estimates (Vintage 2019), built from the 2010 Census plus births, deaths and migration.

12. U.S. Census Bureau, Annual Estimates of the Civilian Population by Single Year of Age and Sex for the United States and States: April 1, 2020 to July 1, 2025 (SC-EST2025-AGESEX-CIV) July 1, 2021-2025 civilian population ages 14-17 by sex and state (denominators for 2021-22 to 2025-26) Free copy

    Retrieved October 23, 2026. Public domain (U.S. government work). Aggregates republished.

    Reliability: Government. Census Bureau population estimates (Vintage 2025), built on the 2020 Census base; not strictly continuous with Vintage 2019.

13. Idaho Legislature, House Bill 500 (2020), Fairness in Women's Sports Act: bill status Idaho enactment date (signed March 30, 2020; effective July 1, 2020)

    Retrieved October 23, 2026. Public government record. Linked.

    Reliability: Government. Official legislative status page; the page notes status updates are unofficial until the journal.

14. NPR, Tennessee Becomes 3rd State This Month To Enact Restrictions For Transgender Athletes (March 27, 2021) Enactment dates for the Mississippi, Arkansas and Tennessee laws

    Retrieved October 23, 2026. News report; cited. Linked.

    Reliability: News report. National news report written at the time of signing.

15. ESPN, Transgender athlete laws by state: Legislation, science, more (August 2023) State-by-state bill numbers and enactment dates for laws enacted 2020-2023, and court blocks

    Retrieved October 23, 2026. News report; cited. Linked.

    Reliability: News report. State-by-state tracker compiled by ESPN reporters; dated August 2023, so it predates the 2024-2025 laws.

16. Trans Athlete (transathlete.com), state policy tracker, Take Action page Wyoming enactment date; Alaska and Virginia listed as policy, not law; count of 29 states

    Retrieved October 23, 2026. Advocacy page; cited. Linked.

    Reliability: Advocacy group. Maintained by an advocate for transgender athletes' inclusion, which opposes these laws; used only for dates and classifications.

17. Axios Columbus, Ohio bill restricting trans health care to take effect in 90 days (January 24, 2024) Ohio HB 68 veto override date

    Retrieved October 23, 2026. News report; cited. Linked.

    Reliability: News report. Local news report on the Senate override vote.

18. New Hampshire Bulletin, Sununu signs bans on trans girls in girls' sports, gender affirming surgeries for minors (July 19, 2024) New Hampshire HB 1205 signing date

    Retrieved October 23, 2026. News report; cited. Linked.

    Reliability: News report. Nonprofit state news outlet reporting the signing.

19. Office of Governor Jim Pillen, Governor Pillen Signs the Stand With Women Act (June 4, 2025) Nebraska LB 89 signing date

    Retrieved October 23, 2026. Public government record. Linked.

    Reliability: Government. Has a stake in this finding. Press release from the governor who signed the law.

20. Nebraska Legislature, LB 89 (2025), Stand With Women Act, slip law Nebraska requirement that every athlete give a doctor-signed document confirming sex

    Retrieved October 23, 2026. Public government record. Linked.

    Reliability: Government. Official slip law published by the Nebraska Legislature.

21. Oklahoma Legislature, SB 2 (2022), enrolled Oklahoma requirement of an annual parent affidavit of sex for every athlete

    Retrieved October 23, 2026. Public government record. Linked.

    Reliability: Government. Enrolled bill text published by the Oklahoma Legislature.

Limitations and reproducibility

Reproducible: All inputs are public. The scripts (artifacts) parse the NFHS PDFs, join Census estimates, and compute every analysis; the README lists the steps. Extracted columns were checked against NFHS national totals.

• Observational: the law states differ from the others (mostly Southern, Plains and Mountain West states with Republican legislatures). A difference in trends is not proof that the laws caused it.
• NFHS figures are reported by each state association and are not audited. Some states repeat an earlier year exactly (Ohio 2022-23 and 2023-24; Connecticut, Delaware, Louisiana, Maine, Vermont and DC in some years), and some jump by more than 25% in a year (for example Vermont +103%, Kentucky +38% and Washington +28% in 2025-26).
• Counts are participation entries, not unique students: a student in two sports counts twice.
• No survey for 2019-20 or 2020-21 (COVID-19). Pandemic limits on school sports lasted longer in some no-law states, which may have slowed their recovery.
• Girls' flag football and wrestling grew fast after 2021, and flag football was sanctioned first in several Southern law states; a version excluding both sports is included.
• The laws differ (grades covered, how sex is established, enforcement), and some were blocked in court for some or all students (Idaho, Utah, Arizona; West Virginia and New Hampshire for named plaintiffs).
• None of these laws requires every girl to have her sex verified by a health care provider as I-638 Sec. 3(2) would; this data cannot test that requirement.
• Census Vintage 2019 (for 2015-2018) and Vintage 2025 (for 2021-2025) use different census bases.
• A federal executive order of February 2025 applied nationwide, so in 2024-25 and 2025-26 the comparison is between states with and without their own law.
• Law states started with lower girls' participation (370 vs 453 per 1,000 in 2018-19), and after the pandemic gap lower-rate states gained more; part of the law states' faster gain may be catch-up (see catch-up-check).