Year	% of cohort
1971	98.9619216918945
1972	98.850959777832
1973	98.9375686645508
1976	97.9518890380859
1977	97.9503021240234
1978	97.2642364501953
1979	95.4771118164062
1981	90.4308090209961
1982	89.9066390991211
1983	88.4818878173828
1984	87.2953262329102
1991	97.5300674438477
1992	97.4722366333008
1993	97.7104263305664
1998	97.2470397949219
1999	96.6640930175781
2000	96.9319610595703
2001	98.5967178344727
2005	97.5549087524414
2006	97.8878173828125
2007	97.2796020507812
2008	97.7054977416992
2009	97.7291564941406
2010	98.1582107543945
2011	98.0738220214844
2012	99.3542861938477
2013	98.529541015625
2014	68.2188262939453
2015	95.5127105712891
2016	98.2127838134766
2017	98.7038116455078
2018	98.6847610473633
2019	98.4032592773438
2020	99.1164627075195