Year	% of total teachers
1999	74.2070236206055
2000	73.0336685180664
2001	73.8339080810547
2002	73.7435531616211
2003	76.2140808105469
2004	81.3381195068359
2005	75.7145385742188
2006	71.8786163330078
2007	70.8494110107422
2008	68.6770782470703
2009	70.036506652832
2010	70.4147796630859
2011	70.4125595092773
2012	71.6922836303711
2013	72.7792663574219
2014	72.3086318969727
2015	73.677360534668
2016	75.7489700317383
2017	76.1511306762695
2018	77.1097793579102
2021	78.1662979125977