Year	% of cohort
1971	96.2964706420898
1972	96.6319732666016
1973	97.5498428344727
1974	97.0322799682617
1976	90.2714996337891
1977	98.8756408691406
1978	97.7918395996094
1980	99.7313385009766
1981	99.1027908325195
1982	98.6506881713867
1983	99.1198425292969
1984	98.6567687988281
1985	98.323371887207
1986	99.2303009033203
1987	98.8368606567383
1988	98.8514175415039
1989	98.2214202880859
1990	98.9335632324219
1991	93.3242263793945
1992	99.8022613525391
1998	99.8117904663086
1999	99.8760681152344
2000	99.9121170043945
2004	91.2036285400391
2007	97.6297836303711
2008	99.4681701660156
2009	98.886833190918
2012	98.3670806884766
2013	99.4801635742188
2014	99.7701110839844
2017	99.7692337036133
2018	99.8103179931641
2019	99.6931381225586
2020	99.7026062011719
2021	99.6180877685547