Year	% of cohort
1981	50.6346282958984
1986	46.4118499755859
1987	41.796760559082
1988	33.6477699279785
1993	53.6380310058594
1994	50.6076316833496
1995	53.0437698364258
1998	50.3237609863281
1999	58.8336601257324
2000	65.7980804443359
2001	58.1114807128906
2002	52.1777687072754
2003	53.9514083862305
2004	69.4619522094727
2005	67.3913421630859
2006	65.3408737182617
2007	52.5946006774902
2008	48.7667388916016
2009	44.3831100463867
2010	49.4671401977539
2011	46.6746788024902
2014	45.186710357666