Year	% of total teachers
2006	77.6409301757812
2007	74.3010635375977
2008	68.7997283935547
2009	65.7012100219727
2010	62.9517097473145
2011	55.3598899841309
2012	60.2323608398438
2013	55.0937995910645
2014	56.7784004211426
2015	57.6740112304688
2016	61.5978393554688
2017	62.3232498168945
2018	64.319580078125
2019	61.2798309326172