Year	% of cohort
1999	97.3215103149414
2001	92.1079711914062
2002	93.7912979125977
2003	94.7168579101562
2004	92.5327377319336
2006	93.6466064453125
2007	88.0566101074219
2008	86.9139862060547
2013	92.3918914794922