Year	% of cohort
1970	58.627498626709
1971	60.1122589111328
1972	62.1089401245117
1973	64.3440322875977
1974	59.5235710144043
1975	58.2544898986816
1976	59.1561813354492
1977	59.7102699279785
1978	61.3535385131836
1979	63.5213203430176
1980	64.667121887207
1981	64.6296615600586
1982	64.2253265380859
1983	64.2956924438477
1984	66.4481582641602
1985	66.0673904418945
1986	67.2874374389648
1987	66.2717971801758
1988	66.3638763427734
1989	67.220832824707
1990	66.967903137207
1991	66.1444702148438
1992	67.9983596801758
1993	72.2313003540039
1994	70.6286468505859
1995	68.2255401611328
1996	69.5222091674805
1997	70.5160675048828
1998	69.1521530151367
1999	69.1426010131836
2000	69.4718322753906
2001	69.2396621704102
2002	70.6409301757812
2003	69.1594924926758
2004	68.9816131591797
2005	69.8992919921875
2006	68.1006469726562
2007	70.34716796875
2008	69.7172088623047
2009	70.2980117797852
2010	69.7872467041016
2011	72.0143280029297
2012	70.6840362548828
2013	72.598388671875
2014	72.7179870605469
2015	72.9011077880859
2016	73.2046737670898
2017	73.4478912353516
2018	73.5225067138672
2019	73.1835174560547