Year % of total teachers 2009 65.3247909545898 2010 63.4348106384277 2011 57.333381652832 2012 60.8652191162109 2013 57.1500091552734 2014 61.444580078125 2015 63.5545501708984 2016 65.9728469848633 2017 66.453857421875 2018 67.6561584472656 2019 64.9429626464844