Year	% of cohort
1971	99.3419418334961
1972	99.2969131469727
1973	99.6115112304688
1974	99.0870666503906
1975	99.3369827270508
1976	99.2807998657227
1977	99.5254135131836
1978	99.2627105712891
1979	96.3053512573242
1980	89.3900527954102
1981	82.0006484985352
1982	76.9851608276367
1983	72.8773574829102
1984	69.2987518310547
1985	66.0568695068359
1989	45.2882881164551
1991	98.0033798217773
1992	99.3589706420898
1993	97.6368179321289
1994	96.199821472168
1995	97.5763473510742
1996	98.0671691894531
1998	93.7077789306641
1999	99.2016830444336
2000	98.8826522827148
2001	96.2185821533203
2002	98.5233612060547
2003	95.9456787109375
2004	99.1104583740234
2005	99.225830078125
2006	99.1669616699219
2007	98.011360168457
2008	99.5029678344727
2009	99.6784286499023
2010	98.1925201416016
2011	99.0633392333984
2012	98.6681365966797
2013	98.3238372802734
2014	98.4325637817383
2015	98.7974700927734
2016	97.8690872192383
2017	98.2668609619141
2018	98.2488479614258
2019	98.2568130493164
2020	98.2639617919922
2021	95.6231994628906