Year	% of cohort
1960	67.203498
1961	68.433723
1962	66.769495
1963	67.916896
1964	68.615667
1965	68.436094
1966	69.479973
1967	68.267372
1968	67.746864
1969	67.607386
1970	66.773103
1971	66.250388
1972	67.363826
1973	67.291063
1974	66.376587
1975	65.849738
1976	66.195409
1977	65.941224
1978	63.798362
1979	63.555559
1980	61.20826
1981	60.778221
1982	60.653946
1983	58.897822
1984	58.246926
1985	58.509562
1986	58.501857
1987	59.221976
1988	59.761012
1989	57.695999
1990	57.267433
1991	57.149563
1992	55.628779
1993	55.055887
1994	55.759189
1995	56.800107
1996	58.988529
1997	59.806942
1998	59.112352
1999	59.59728
2000	61.567145
2001	63.330842
2002	63.43808
2003	63.450281
2004	64.008405
2005	63.791687
2006	64.548047
2007	64.998168
2008	66.151692
2009	66.714778
2010	67.786166
2011	69.076099
2012	70.334909
2013	71.787013
2014	71.954226
2015	72.099565
2016	72.67283
2017	72.91295
2018	73.030319
2019	73.976514
2020	72.929707
2021	70.909985
2022	71.607961