Year	% of cohort
1971	99.2543182373047
1972	97.2572021484375
1973	98.5316925048828
1974	98.8440628051758
1975	96.6983795166016
1976	99.2786407470703
1977	98.9568176269531
1978	98.8345718383789
1979	99.3918533325195
1980	99.364372253418
1981	99.5065994262695
1984	99.2179183959961
1985	99.7268905639648
1986	98.9979934692383
1987	99.4556579589844
1988	99.4007797241211
1989	98.3658294677734
1990	98.9962768554688
1991	99.3856735229492
1992	98.3817367553711
1998	98.905517578125
1999	99.5825881958008
2000	99.0408477783203
2001	98.9943313598633
2002	99.1601486206055
2003	99.2489700317383
2004	99.8310165405273
2005	99.1670608520508
2006	99.4112930297852
2007	98.9249420166016
2008	99.4709014892578
2009	99.0988616943359
2010	99.2851867675781
2011	98.4884490966797
2012	98.5401992797852
2013	99.5749130249023
2014	99.474853515625
2015	99.5584335327148
2016	99.1022033691406
2017	99.1886596679688
2018	99.3975982666016
2019	99.1438827514648
2020	99.2265167236328