Year	% of total teachers
2006	85.9473419189453
2008	83.6554336547852
2010	80.2370681762695
2011	79.7350616455078
2012	80.6915130615234
2013	79.3641967773438
2014	78.7228469848633
2015	78.9660186767578
2016	78.3114471435547
2017	80.2251586914062
2018	79.8312911987305
2019	78.2807998657227
2020	77.5665588378906
2021	77.2069473266602