Year	% of cohort
1971	42.0910797119141
1972	40.2061004638672
1973	39.4659004211426
1974	39.2514610290527
1975	39.7329216003418
1976	50.8610916137695
1977	50.7934989929199
1978	45.8110504150391
1979	45.9554290771484
1980	41.6103286743164
1981	50.1908988952637
1983	56.3743705749512
1984	47.1288681030273
1991	71.7324066162109
1992	70.915412902832
1993	74.0058288574219
2000	80.1327667236328
2001	84.6197204589844
2002	83.7102508544922
2003	80.6246566772461