Year	% of cohort
1973	66.5497589111328
1974	63.7668304443359
1975	62.6580581665039
1976	63.4856986999512
1977	64.0593109130859
1978	65.7332229614258
1979	66.8644790649414
1980	68.1531219482422
1981	67.8841934204102
1982	67.4474716186523
1983	67.2096481323242
1984	68.1295776367188
1985	67.5974273681641
1986	67.9481887817383
1987	67.382080078125
1988	67.5646591186523
1989	68.5367965698242
1990	68.0763168334961
1991	67.9862823486328
1992	69.3672103881836
1993	71.8247222900391
1994	70.7973403930664
1995	68.9097213745117
1996	70.2497329711914
1997	70.7935028076172
1998	69.8004608154297
1999	69.6025695800781
2000	69.4152526855469
2001	70.0647811889648
2002	70.76904296875
2003	70.1396026611328
2004	69.8745498657227
2005	71.0860137939453
2006	69.6762390136719
2007	71.7986907958984
2008	71.1125717163086
2009	71.9194412231445
2010	71.4209976196289
2011	73.3889923095703
2012	72.9042205810547
2013	74.3808822631836
2014	74.6618804931641
2015	74.8264389038086
2016	74.3610687255859
2017	74.3097534179688
2018	74.0521697998047
2019	72.8404388427734
2020	72.2023086547852