Year	% of cohort
1960	37.412933
1961	37.990351
1962	38.89419
1963	39.617636
1964	40.625722
1965	41.335154
1966	41.320016
1967	42.165171
1968	42.825274
1969	43.433162
1970	44.00856
1971	44.624416
1972	45.205249
1973	45.865141
1974	46.196077
1975	46.719494
1976	47.146951
1977	47.576231
1978	48.032214
1979	48.153723
1980	41.438597
1981	41.651933
1982	42.366948
1983	42.947151
1984	43.897107
1985	44.671772
1986	45.462361
1987	46.671842
1988	46.374697
1989	53.208476
1990	52.74261
1991	51.707036
1992	50.420164
1993	48.805463
1994	46.385999
1995	43.616885
1996	40.145628
1997	37.0466
1998	34.202389
1999	31.798824
2000	29.799476
2001	28.5005
2002	28.174678
2003	27.990012
2004	27.885367
2005	28.416078
2006	28.796009
2007	29.763921
2008	30.598906
2009	31.559655
2010	32.587913
2011	33.425418
2012	35.580797
2013	37.524528
2014	40.199756
2015	42.06613
2016	43.781185
2017	44.846239
2018	45.462356
2019	46.569864
2020	45.280607
2021	36.741778
2022	34.105225