Year	% of cohort
1971	96.5577392578125
1972	97.2917861938477
1973	96.3101272583008
1974	97.728889465332
1975	96.7098770141602
1976	97.539436340332
1977	95.6653900146484
1978	92.2217712402344
1979	95.4685211181641
1980	97.2321701049805
1981	99.0501174926758
1982	99.3785781860352
1983	99.2422790527344
2008	99.3373565673828
2016	99.3924407958984
2017	99.7114562988281
2018	99.6050262451172
2019	99.6588516235352
2020	99.751350402832