Year	% of cohort
1960	51.212161
1961	52.395887
1962	49.517878
1963	54.802505
1964	55.932941
1965	56.777975
1966	58.160931
1967	59.167972
1968	59.967429
1969	60.858892
1970	61.751907
1971	62.625931
1972	63.58716
1973	64.418897
1974	65.095299
1975	65.888189
1976	66.488821
1977	67.001671
1978	67.44236
1979	67.798278
1980	68.10864
1981	68.370444
1982	68.606046
1983	68.842046
1984	69.130577
1985	69.325981
1986	69.66288
1987	69.948193
1988	70.244056
1989	70.549977
1990	70.872463
1991	71.263614
1992	71.598864
1993	72.020291
1994	72.471798
1995	72.947963
1996	73.482176
1997	73.972605
1998	74.455159
1999	74.913958
2000	75.33012
2001	75.730806
2002	76.016401
2003	76.312783
2004	76.496614
2005	76.691412
2006	76.811908
2007	76.896544
2008	76.953976
2009	76.962028
2010	76.979081
2011	77.015431
2012	76.978371
2013	76.964553
2014	76.950352
2015	76.947813
2016	76.968592
2017	77.003339
2018	77.034449
2019	77.165098
2020	77.295191
2021	77.456628
2022	77.29723