Year	% of total teachers
2006	87.053092956543
2007	80.2122116088867
2008	58.5803604125977
2009	50.0365715026855
2010	42.3634910583496
2011	33.9890098571777
2012	47.4916381835938
2013	40.6771583557129
2014	53.4352989196777
2015	55.3491706848145
2016	58.782958984375
2017	62.216911315918
2018	62.8250007629395
2019	59.7757415771484