Year	% of cohort
1960	44.844481
1961	46.228092
1962	47.508226
1963	48.56393
1964	49.272171
1965	49.364494
1966	49.303012
1967	48.892425
1968	48.545978
1969	48.578372
1970	49.346859
1971	50.787104
1972	52.552374
1973	54.453717
1974	56.087443
1975	57.268823
1976	57.998029
1977	58.444938
1978	58.777853
1979	58.770251
1980	53.842415
1981	58.993117
1982	59.303866
1983	61.817229
1984	63.485623
1985	65.03003
1986	65.259274
1987	67.654255
1988	69.067289
1989	69.502214
1990	71.229988
1991	72.429946
1992	73.445437
1993	74.346243
1994	75.169366
1995	75.704258
1996	76.350701
1997	76.991313
1998	77.121798
1999	78.157842
2000	78.68552
2001	78.119689
2002	79.610005
2003	79.747807
2004	80.328002
2005	80.488902
2006	80.807861
2007	80.989045
2008	81.139096
2009	81.062219
2010	81.541429
2011	81.769357
2012	82.006046
2013	82.153244
2014	82.20117
2015	82.112093
2016	81.952403
2017	81.848027
2018	82.029662
2019	82.595745
2020	80.496534
2021	80.030848
2022	80.9259