Year	% of cohort
1972	75.328239440918
1973	76.3408813476562
1975	78.6467971801758
1976	74.2766189575195
1977	78.6871795654297
1978	73.9036483764648
1983	77.670768737793
1984	82.2711563110352
1989	69.61669921875
1991	67.6681213378906
1993	64.0625381469727
1995	78.4020767211914
2002	68.5163421630859
2007	79.3477096557617