Year	% of expense
2003	36.90702218710451
2007	38.9250640168288
2008	43.203632521686075
2009	44.229151121063985
2010	42.00899671700773
2011	46.87321264418924
2012	47.61521329168815
2013	47.245549686478014
2014	48.1077585937789
2015	46.98557504008248
2016	46.792920860563854
2017	46.5545357598166
2018	46.44524741426845
2019	46.23251850368413
2020	47.34232030909282
2021	46.63596818511411
2022	39.11606956882503