Year	% of total teachers
1997	53.9142112731934
1998	70.4812927246094
1999	70.5869903564453
2000	71.3333892822266
2001	69.6898193359375
2002	69.1888122558594
2003	68.1404495239258
2004	70.0607528686523
2005	67.1946792602539
2006	67.592903137207
2007	67.3168182373047
2008	69.5434417724609
2009	65.3047027587891
2010	67.2537612915039
2011	68.1639099121094
2012	67.1180572509766
2013	66.3073883056641
2014	64.1478500366211
2015	62.4218597412109
2016	61.8502006530762
2017	61.0169792175293
2018	63.0177307128906
2019	62.7748107910156
2020	64.061408996582