Year	% of cohort
1960	33.059451
1961	32.37679
1962	35.316043
1963	36.611077
1964	37.745238
1965	39.097222
1966	40.473295
1967	41.885094
1968	43.51421
1969	44.845723
1970	46.751052
1971	47.925142
1972	49.732973
1973	51.541621
1974	53.397761
1975	55.496908
1976	57.113391
1977	59.038642
1978	60.166301
1979	61.279062
1980	62.519094
1981	63.782541
1982	64.902199
1983	66.150728
1984	67.294631
1985	68.398671
1986	69.548501
1987	70.646465
1988	72.093469
1989	71.848129
1990	72.169679
1991	72.502236
1992	72.724613
1993	73.344483
1994	73.929253
1995	74.267158
1996	74.770181
1997	75.296133
1998	75.481139
1999	75.944594
2000	76.229044
2001	76.462615
2002	76.709307
2003	76.965679
2004	77.17016
2005	77.384883
2006	77.570062
2007	77.716615
2008	77.913595
2009	78.008678
2010	78.151185
2011	78.114077
2012	78.363922
2013	78.499306
2014	78.515473
2015	78.567425
2016	78.451289
2017	78.630432
2018	78.735812
2019	78.844821
2020	77.469492
2021	74.967361
2022	76.150226