Year	% of cohort
1971	97.8063430786133
1972	97.8515319824219
1973	98.6358413696289
1981	99.1472015380859
1982	98.8511962890625
1983	99.0886383056641
1984	99.5788726806641
1985	97.4738922119141
1986	99.6775588989258
1987	98.9933319091797
1988	99.0968017578125
1989	98.6131286621094
1990	99.24072265625
1991	94.1250686645508
1992	99.9609375
1998	99.8221130371094
1999	99.9116287231445
2000	99.9773483276367
2004	92.376708984375
2005	99.7578582763672
2007	99.2048797607422
2008	99.5861968994141
2009	99.3249893188477
2012	99.5882034301758
2013	99.5877532958984
2014	99.9362716674805
2016	99.6795806884766
2017	99.8820266723633
2018	99.822998046875
2019	99.8524017333984
2020	99.8117065429688
2021	99.5083694458008