Year	% of total teachers
2005	79.1672515869141
2008	70.1530685424805
2009	64.7906112670898
2011	62.8837585449219
2012	64.8368606567383
2013	59.7521705627441
2014	58.1455116271973
2015	58.168399810791
2016	59.2935409545898
2017	58.6382484436035
2018	59.2430992126465
2019	58.0870780944824