Year	% of cohort
1977	71.8838500976562
1988	67.7838516235352
1989	51.8298606872559
1990	72.7264709472656
1991	73.6110076904297
1992	73.4198684692383
1993	68.8499069213867
1994	62.2030181884766
1995	56.358570098877
1996	58.4647598266602
1997	58.341438293457
1998	56.4422492980957
2001	40.4291915893555
2004	39.3740081787109
2005	44.5829010009766
2006	54.4830703735352
2008	81.2377700805664
2012	64.1279296875
2016	64.8940505981445
