Year	% of cohort
1971	93.9190979003906
1972	94.6515426635742
1973	94.7807464599609
1974	95.1606369018555
1975	95.9288101196289
1976	95.8976287841797
1977	95.8503799438477
1978	95.9909591674805
1979	97.0738830566406
1980	96.4140472412109
1981	96.7199096679688
1982	97.2178726196289
1983	97.059196472168
1984	97.1319427490234
1985	96.8334121704102
1986	96.6302108764648
1987	96.738410949707
1988	97.7481079101562
1989	97.8121032714844
1990	98.2275772094727
1991	97.6388626098633
1992	97.557746887207
1996	96.0652236938477
1997	93.7869567871094
1998	96.0758514404297
1999	96.4289321899414
2000	94.4132766723633
2001	96.5468063354492
2002	97.3600234985352
2003	97.2941589355469
2004	97.9969024658203
2005	98.0314178466797
2006	97.9540405273438
2007	98.6686096191406
2008	97.6984481811523
2009	98.0723037719727
2010	98.4797592163086
2011	98.4473724365234
2012	97.9692687988281
2013	98.2601699829102
2014	97.9147720336914
2015	98.4291610717773
2016	97.3747024536133
2017	98.901969909668
2018	98.9182968139648
2019	98.8434600830078
2020	98.9421081542969