Year	% of cohort
1960	30.659621
1961	31.305127
1962	31.723437
1963	32.196588
1964	32.373211
1965	32.810432
1966	33.633408
1967	34.93581
1968	36.57386
1969	38.180527
1970	39.763877
1971	41.257888
1972	42.716359
1973	43.532063
1974	44.284533
1975	42.608617
1976	45.64896
1977	46.187485
1978	47.078934
1979	47.639022
1980	48.160558
1981	48.652599
1982	49.181885
1983	49.382909
1984	50.255925
1985	50.800201
1986	51.438247
1987	51.512071
1988	52.126811
1989	52.570497
1990	53.05094
1991	53.365455
1992	54.394471
1993	55.576355
1994	56.169144
1995	56.968785
1996	57.555355
1997	58.442295
1998	58.274567
1999	58.898372
2000	58.663791
2001	59.384314
2002	59.167256
2003	59.509999
2004	60.30847
2005	60.495044
2006	60.764319
2007	61.368094
2008	61.686569
2009	62.790415
2010	62.98276
2011	63.959739
2012	64.175918
2013	65.256503
2014	65.394232
2015	66.557864
2016	66.720288
2017	67.961521
2018	68.187757
2019	68.234938
2020	68.70467
2021	66.811497
2022	67.365143
