Year % of cohort 1980 93.3637619018555 1981 94.1834869384766 1982 93.4372100830078 1983 93.9722366333008 1984 97.2213516235352 1985 95.9830474853516 1986 99.7973022460938 1989 96.6789932250977 2005 99.2837905883789 2008 99.9977416992188 2009 95.26318359375 2010 98.2278289794922 2011 97.5633773803711 2012 97.2459106445312 2013 97.8073425292969 2014 98.4912490844727 2015 99.3617630004883 2016 99.9814605712891 2017 100 2018 99.9855117797852 2019 99.7720336914062 2020 100