Year	% of total teachers
1999	69.4783325195312
2000	69.8896789550781
2001	65.0797882080078
2002	66.4202194213867
2004	84.3047103881836
2006	95.3918609619141
2007	97.0991973876953
2008	97.8488082885742
2009	96.0500717163086
2010	98.8184432983398
2014	93.8253631591797
2016	91.786750793457
2017	93.0310211181641
2018	88.9854202270508