Year	% of expense
2005	26.3096649287086
2006	24.163141806704562
2007	24.34251166771958
2008	16.43103965160863
2009	17.46883176850854
2010	17.206703910614525
2011	17.20595559321782
2012	16.5695235733096
2013	16.061459941388247
2014	15.585006535090642
2015	15.538462058269129
2016	15.954341093555158
2017	15.34967630219225
2018	14.514352343365964
2019	13.707928369862572
2020	12.879335089061229
2021	12.953578861641478