Year	% of cohort
1971	65.6844635009766
1972	66.3593368530273
1974	66.4357223510742
1976	75.6086807250977
1977	75.617317199707
1978	77.9085311889648
1980	80.1377792358398
1985	83.4614105224609
1998	73.0250701904297
1999	78.1031188964844
2005	85.3943176269531
2006	83.4366989135742
2007	87.178581237793
2008	70.4443511962891
2009	78.17529296875
2012	73.2956619262695