Year	% of cohort
1970	66.5224914550781
1978	92.7650299072266
1980	84.2183380126953
1982	94.1712875366211
1983	90.7640686035156
1984	93.0538177490234
1985	90.7131271362305
1986	94.5342178344727
1987	93.536750793457
1989	92.2004013061523
1990	97.5990219116211
1991	86.51416015625
1992	90.6892700195312
1993	91.8647232055664
1994	88.1173706054688
1995	93.0881805419922
1998	91.0943222045898
1999	88.981071472168
2000	91.8525009155273
2001	89.9248428344727
2002	91.7795486450195
2003	92.0149993896484
2004	93.2595291137695
2005	89.2889022827148
2008	97.4856567382812
2012	97.4954986572266