Year	% of total teachers
2006	82.8206100463867
2007	76.9461898803711
2008	67.9898681640625
2009	66.6559066772461
2010	57.5901718139648
2011	46.1951599121094
2012	54.9591484069824
2013	49.2662086486816
2014	54.765251159668
2015	57.3488998413086
2016	65.3330383300781
2017	67.6566314697266
2018	71.3804092407227
2019	65.3493728637695