Year	% of total teachers
2007	93.2130966186523
2008	88.8822631835938
2009	88.4487686157227
2010	86.3913497924805
2011	82.859260559082
2012	86.3233413696289
2013	80.6750793457031
2018	86.2321929931641
2019	76.431266784668
2020	76.2577590942383
2021	77.1371383666992
2022	75.9311981201172