Year	% of cohort
1971	25.5771808624268
1972	43.4041290283203
1973	44.1773986816406
1975	66.2593765258789
1977	43.0454292297363
1980	35.1553688049316
1981	50.6285018920898
1982	37.6624488830566
1985	66.7910537719727
1986	21.1263198852539
1987	58.0030784606934
1988	53.8917007446289
1990	32.0782585144043
1991	22.5978698730469
2008	48.4660911560059
2009	50.2169609069824
2010	51.3503189086914
2011	55.9883918762207