Year	% of cohort
1970	39.0425910949707
1971	38.9067687988281
1972	39.1600685119629
1973	40.6243782043457
1974	42.4463882446289
1975	42.3688697814941
1976	42.654411315918
1977	44.53173828125
1978	43.4338684082031
1979	43.4513893127441
1980	42.916130065918
1981	42.7745590209961
1982	44.6522903442383
1983	45.3827590942383
1984	46.2449913024902
1985	48.4891815185547
1986	49.6408004760742
1987	50.04248046875
1988	50.2386283874512
1989	50.5076599121094
1990	51.5353584289551
1991	51.3544998168945
1992	53.1943702697754
1993	52.7236709594727
1994	52.5175094604492
1995	53.6268196105957
1996	53.0888404846191
1997	53.2087097167969
1998	52.7764091491699
1999	55.0697212219238
2000	56.9595108032227
2001	59.2295799255371
2002	59.0724411010742
2003	57.5980110168457
2004	58.4586486816406
2005	58.146728515625
2006	58.8386993408203
2007	58.0489387512207
2008	56.5209312438965
2009	54.7419013977051
2010	54.1121292114258
2011	55.3001289367676
2012	53.7519989013672
2013	53.08251953125
2014	53.4945793151855
2015	54.7895698547363
2016	55.023120880127
2017	56.6798400878906
2018	56.9171295166016
2019	57.5704002380371
2020	58.8815002441406