Year	% of expense
2008	10.247190228142145
2009	10.042787534922908
2010	10.246137153718223
2011	8.91334338323467
2012	8.353287130865377
2013	10.032164957883815
2014	10.410657724683176
2015	13.253847498093094
2016	15.458023851146487
2017	13.578819677534007
2018	12.381880356190909
2019	14.524123780297716
2020	29.390688427945427