Year	% of cohort
1960	43.317482
1961	43.903806
1962	44.487855
1963	45.162921
1964	45.66149
1965	46.256727
1966	46.746672
1967	47.198656
1968	47.432161
1969	48.093496
1970	48.678731
1971	48.902509
1972	49.317102
1973	48.914088
1974	49.213168
1975	49.556439
1976	47.148333
1977	44.695787
1978	38.534778
1979	39.337101
1980	51.170596
1981	51.561583
1982	52.146699
1983	52.178274
1984	53.176507
1985	53.259887
1986	53.112328
1987	51.581094
1988	50.549875
1989	47.947431
1990	45.84878
1991	43.57007
1992	40.036828
1993	36.035382
1994	32.206606
1995	28.093351
1996	25.54948
1997	23.240536
1998	20.527941
1999	17.619461
2000	16.990798
2001	14.019486
2002	17.380028
2003	16.542166
2004	17.872483
2005	18.816963
2006	19.78689
2007	21.029755
2008	22.73187
2009	24.624496
2010	28.732649
2011	32.985712
2012	36.971638
2013	40.360086
2014	43.285209
2015	44.734556
2016	45.829358
2017	46.191019
2018	47.657356
2019	46.791842
2020	44.917408
2021	40.235315
2022	41.037746