Year	% of cohort
1970	52.7761993408203
1971	53.4587898254395
1972	53.8617401123047
1973	55.0597305297852
1974	58.4894599914551
1975	58.7259712219238
1976	58.5462608337402
1977	60.6791801452637
1978	58.4360084533691
1979	57.8633117675781
1980	57.3852081298828
1981	55.523120880127
1982	57.785831451416
1983	56.5410995483398
1984	56.1808280944824
1985	58.2172012329102
1986	59.2202682495117
1987	57.5455284118652
1988	55.7840194702148
1989	55.8179512023926
1990	56.4832382202148
1991	55.7542915344238
1992	57.8344993591309
1993	56.8537101745605
1994	54.9865608215332
1995	56.1795082092285
1996	54.6626586914062
1997	54.2310409545898
1998	53.7154693603516
1999	55.9445915222168
2000	58.7747116088867
2001	61.6191902160645
2002	59.707878112793
2003	57.4474601745605
2004	58.9552307128906
2005	58.3946495056152
2006	59.3155097961426
2007	58.0561218261719
2008	56.0775718688965
2009	53.5919609069824
2010	52.686710357666
2011	54.9856605529785
2012	53.000301361084
2013	52.6091384887695
2014	53.0478096008301
2015	54.251049041748
2016	53.9644317626953
2017	55.7083206176758
2018	57.0036582946777
2019	57.867431640625
2020	59.2985305786133
2021	59.0525894165039