Year	% of cohort
1977	91.2247161865234
1978	92.34423828125
1980	90.12548828125
1981	89.3581008911133
1982	86.4727630615234
1983	82.7311401367188
1986	83.7846908569336
1987	85.3179779052734
1989	87.1625823974609
1991	86.4090270996094
1992	84.4151077270508
1994	86.5383377075195
1996	95.401496887207
2001	71.8572387695312
2003	79.7339324951172
2005	80.6206970214844
2006	78.5713119506836