Year	% of cohort
1974	93.1429061889648
1975	88.2778778076172
1980	89.0127563476562
1981	80.3113174438477
1982	91.6263427734375
1983	86.5311889648438
1985	84.9930801391602
1986	77.6949234008789
1987	75.0298690795898
1988	78.8200225830078
1990	76.7087783813477
1991	81.1864700317383
1992	81.1360092163086
1993	76.2237014770508
1996	78.4645080566406
1997	74.3708572387695
1998	78.668083190918
1999	79.787712097168
2000	79.5268630981445
2001	96.3662414550781
2003	86.0631484985352
2004	83.6704025268555
2005	83.568977355957
2006	84.9238433837891
2008	78.7757110595703
2009	87.0441436767578
2012	75.2189788818359
2015	55.6170883178711
2017	93.8599395751953
2018	86.8843765258789
2019	81.8549118041992