Year	% of cohort
1970	91.3549270629883
1971	89.9769668579102
1973	91.3999481201172
1974	91.2200698852539
1975	83.3221206665039
1977	88.8892288208008
1979	88.9655609130859
1980	96.4415130615234
1981	96.9519729614258
1982	94.8026580810547
1983	96.5489807128906
1984	98.1902236938477
1985	95.0735473632812
1986	94.0155487060547
1987	94.7056579589844
1988	95.2953262329102
1991	92.6680679321289
1992	94.6103591918945
1993	95.3745422363281
1996	95.3348617553711
1997	94.4756774902344
1998	95.923698425293
1999	96.3461227416992
2000	90.9532699584961
2001	97.7967910766602
2002	98.3230285644531
2003	88.300163269043
2007	92.3402328491211
2008	94.929801940918
2009	95.5607604980469
2010	96.0432586669922
2013	87.9436264038086
2014	92.309440612793
2015	97.0737075805664
2017	96.8130569458008
2018	97.178337097168
2019	96.608642578125
2020	95.8308181762695
2021	95.7430114746094