Year % of total teachers 2006 81.6224594116211 2007 81.7975921630859 2008 80.2801208496094 2009 78.8066177368164 2010 79.1185607910156 2011 78.6424026489258 2012 77.868766784668 2013 76.0236129760742 2014 76.4876403808594 2015 74.0536499023438 2016 73.9916534423828 2017 74.3134765625 2018 74.2969284057617 2019 77.8742828369141 2020 75.9108428955078 2021 77.7391586303711 2022 75.2601623535156