Year	% of cohort
1972	97.8913803100586
1973	96.8775634765625
1974	98.0973129272461
1975	96.3734970092773
1976	98.0162811279297
1977	94.963752746582
1978	89.9446334838867
1979	94.3202896118164
1981	100
1983	100
2008	99.2429504394531
2016	100
2017	99.8285217285156
2018	99.4090118408203
2019	99.4414901733398
2020	99.5173110961914