Year	% of cohort
1999	96.0567169189453
2001	98.7951812744141
2002	95.9176483154297
2003	95.0455017089844
2004	95.5102233886719
2006	95.1915969848633
2007	88.3397903442383
2008	99.4350280761719
2013	99.737190246582