Year % of cohort 1991 61.1105003356934 1993 79.9085998535156 1997 84.2010803222656 1998 79.845458984375 1999 92.4471435546875 2002 86.6532669067383 2003 79.8739318847656 2004 84.2715911865234 2005 84.1528167724609 2008 90.28369140625 2009 91.7006988525391 2012 96.2524032592773 2017 89.5967788696289