Year	% of total teachers
1999	66.793830871582
2000	58.901969909668
2003	59.9491195678711
2004	59.3495407104492
2005	54.8306083679199
2006	55.0328712463379
2007	62.2463188171387
2008	61.9201812744141
2009	61.8304405212402
2010	61.3447494506836
2011	61.5050010681152
2012	61.8081703186035
2013	62.2747497558594
2014	61.9216995239258
2015	64.2897109985352
2016	61.0064392089844
2017	60.7775497436523
2018	61.7288703918457
2020	66.4269638061523