Year % of cohort 1983 97.1474380493164 2003 88.7245330810547 2004 96.1410675048828 2006 92.044189453125 2007 93.381950378418 2008 92.6549530029297 2009 95.9607696533203 2010 90.0008392333984 2011 95.4547119140625 2012 94.9699325561523 2013 93.0767288208008 2016 91.078239440918 2017 92.1804962158203 2018 94.1074981689453 2019 93.7482299804688