Year	% of cohort
1991	63.329158782959
1993	82.0451278686523
1994	75.7226715087891
1995	78.6239471435547
1997	86.3855667114258
1998	83.4256973266602
1999	92.7644805908203
2000	90.9353713989258
2001	91.6174087524414
2002	88.1322402954102
2003	82.0246887207031
2004	86.1242904663086
2005	86.8991775512695
2008	91.485237121582
2009	92.8262100219727
2012	96.595588684082
2017	91.5692596435547