Year % of cohort 2008 97.749153137207 2009 99.5094909667969 2010 98.7925415039062 2011 98.5889205932617 2012 97.7603073120117 2013 97.8756637573242 2014 97.9974670410156 2015 98.2876129150391 2016 94.3692474365234 2017 99.5956802368164 2018 99.4494018554688 2021 100