Year	% of total teachers
2009	61.7515983581543
2010	59.7824287414551
2011	55.8421287536621
2012	54.763069152832
2013	53.9259605407715
2014	54.0664405822754
2015	56.1902503967285
2016	56.7492485046387
2017	58.2344284057617
2018	60.755989074707
2019	58.0600090026855