Year	% of cohort
1971	94.9567413330078
1972	96.2157592773438
1973	95.2781600952148
1974	93.7165832519531
1975	97.95458984375
1976	97.9619293212891
1977	97.271110534668
1978	97.3620300292969
1979	93.8928070068359
1980	98.2727279663086
1981	98.3048324584961
1982	99.0941619873047
1983	99.3174133300781
1984	99.8453826904297
1985	98.955680847168
1986	94.0087203979492
1987	99.2075424194336
1988	97.8070983886719
1991	99.3194885253906
2004	97.9496688842773
2005	97.7508163452148
2006	97.6005325317383
2010	93.7138519287109
2011	95.1337814331055
2012	92.1032104492188
2013	93.030517578125
2015	96.1793823242188
2016	98.8203201293945
2017	98.1363296508789
2018	99.5101089477539
2019	99.6374664306641
2020	99.5314102172852