Year	% of cohort
1971	96.1253280639648
1972	93.0811767578125
1973	94.2316513061523
1974	95.3534164428711
1975	95.1879577636719
1976	93.7925262451172
1977	95.9783401489258
1978	96.5421524047852
1979	97.6272277832031
1981	93.9861297607422
1982	97.2567977905273
1983	97.3198394775391
1984	98.9560317993164
1985	99.398567199707
1986	99.394889831543
1987	99.3724822998047
1988	99.439453125
1989	99.5208969116211
1990	99.9256286621094
1991	99.614387512207
1992	99.6644287109375
1993	99.5237808227539
1994	99.5277481079102
1997	97.3487777709961
1998	99.1820373535156
1999	99.3328094482422
2000	99.2399520874023
2001	98.9555435180664
2002	99.71484375
2003	98.1592864990234
2004	98.9659729003906
2005	99.2821731567383
2006	97.9395980834961
2007	98.9255676269531
2008	99.0602722167969
2009	99.3884506225586
2010	99.1841201782227
2011	99.3628997802734
2012	99.5781936645508
2013	99.3673095703125
2014	99.619270324707
2015	99.4469680786133
2016	99.5065002441406
2017	99.2970733642578
2018	99.3391189575195
2019	99.2031402587891
2020	99.7165985107422
2021	98.8273162841797