Year	% of cohort
1971	94.6939086914062
1972	87.2159805297852
1973	93.7747497558594
1974	91.8823318481445
1975	87.6294021606445
1976	93.0396728515625
1977	84.2134628295898
1978	91.3965911865234
1979	91.7076416015625
1980	91.3536987304688
1983	93.3656768798828
1984	97.3389129638672
1989	90.3894805908203
1992	93.2674026489258
1993	98.4565200805664
1994	96.2695083618164
1995	99.2035064697266
2005	85.0273895263672
2007	96.7604370117188
2012	96.18505859375
2016	95.3088073730469
2017	97.9543991088867
2018	87.2455673217773
2019	94.5834274291992
2020	84.6809310913086
2021	93.9595108032227