Year	% of cohort
1986	69.6886672973633
1987	66.1256484985352
1988	66.6719589233398
1989	53.9587593078613
1990	58.4808616638184
1991	68.2459564208984
1994	59.527458190918
1995	60.782169342041
1996	60.3149299621582
1997	63.9672508239746