Year	% of cohort
1971	96.3161163330078
1972	96.7421417236328
1973	97.6854629516602
1974	97.0400924682617
1975	99.5342407226562
1976	92.7251586914062
1977	98.8756408691406
1978	98.1267318725586
1980	99.7313385009766
1981	99.1031723022461
1982	98.8180236816406
1983	99.1426010131836
1984	98.8291320800781
1985	98.601692199707
1986	99.2918395996094
1987	99.1457824707031
1988	99.000129699707
1989	98.6695175170898
1990	99.2268524169922
1991	94.2072677612305
1992	99.8686981201172
1998	99.8365478515625
1999	99.8934478759766
2000	99.9323577880859
2004	92.476432800293
2005	99.7546615600586
2007	98.6549530029297
2008	99.6617279052734
2009	99.2833023071289
2012	99.4903564453125
2013	99.6596908569336
2014	99.9285736083984
2016	99.5678405761719
2017	99.8414993286133
2018	99.8543167114258
2019	99.8645706176758
2020	99.8225631713867
2021	99.727897644043