Year	% of cohort
1960	51.617663
1961	51.893786
1962	52.495371
1963	53.068424
1964	53.607703
1965	54.225664
1966	54.823611
1967	54.917757
1968	55.224483
1969	55.193214
1970	55.732795
1971	56.044576
1972	56.441902
1973	56.781751
1974	57.062451
1975	57.074426
1976	57.119914
1977	57.045612
1978	57.039109
1979	57.431161
1980	59.584319
1981	61.093097
1982	61.739794
1983	62.313124
1984	63.337775
1985	64.586409
1986	65.583473
1987	65.122038
1988	63.669858
1989	61.801964
1990	59.468611
1991	55.731008
1992	52.263489
1993	47.642524
1994	43.568091
1995	39.078839
1996	34.769641
1997	32.712546
1998	30.415121
1999	26.625796
2000	24.107362
2001	16.862963
2002	22.422595
2003	19.35239
2004	22.02572
2005	22.372517
2006	24.029163
2007	24.145536
2008	27.027472
2009	30.206498
2010	35.407287
2011	41.977238
2012	46.186984
2013	49.630847
2014	52.195667
2015	53.853432
2016	55.326969
2017	56.396584
2018	57.579551
2019	57.729252
2020	58.110161
2021	54.30757
2022	54.538231