Year	% of cohort
1971	73.3496780395508
1972	73.4893798828125
1973	77.8893890380859
1974	72.1358032226562
1975	79.1108779907227
1976	80.2380599975586
1977	80.1066513061523
1978	81.8891067504883
1979	84.5598373413086
1980	84.3227233886719
1985	86.0243988037109
1998	78.2000732421875
1999	80.5950393676758
2001	92.9312515258789
2005	87.6465225219727
2006	88.4860000610352
2007	89.0728302001953
2008	70.9723205566406
2009	79.6797409057617
2012	74.4586029052734