Year	% of cohort
1972	96.6517105102539
1973	95.7057800292969
1974	97.3402328491211
1975	97.0664672851562
1976	97.0825500488281
1977	96.3827362060547
1978	94.7136077880859
1979	96.6239395141602
1981	98.0235137939453
1983	98.4261322021484
2008	99.435432434082
2016	98.7624206542969
2017	99.5886077880859
2018	99.8122711181641
2019	99.890266418457
2020	100