Year	% of total teachers
2002	84.3951797485352
2003	80.9395370483398
2004	75.1947326660156
2005	75.2506637573242
2006	75.9946899414062
2007	78.9462432861328
2008	79.284309387207
2009	78.0777816772461
2010	76.7405090332031
2011	74.5641403198242
2012	78.2701034545898
2013	73.8276596069336
2014	73.6801071166992
2015	73.4430084228516
2016	72.7626037597656
2017	72.1921463012695
2018	71.6379013061523
2019	72.1596832275391
2021	71.0408706665039