Year	% of total teachers
2004	89.402458190918
2005	85.9574279785156
2006	84.8110427856445
2007	84.9035186767578
2008	83.7218322753906
2012	87.8716201782227
2013	83.6420135498047
2014	81.389518737793
2015	77.8999710083008
2016	75.8655014038086
2017	75.7378234863281
2018	74.633918762207
2019	73.4021606445312
2020	71.9446792602539
2021	69.8120727539062
2022	76.1912536621094