Year	% of total teachers
2000	88.6328506469727
2001	86.8213729858398
2002	87.3448715209961
2003	83.6688537597656
2004	77.3561935424805
2005	76.31005859375
2006	77.7408981323242
2007	79.8085174560547
2008	79.1143569946289
2009	78.5336380004883
2010	76.0775680541992
2011	74.6679077148438
2012	78.5507278442383
2013	74.1371994018555
2014	72.5885391235352
2015	72.7157211303711
2016	72.5562515258789
2017	71.2497634887695
2018	70.5245132446289
2019	71.0104598999023
2020	70.8370819091797