Year	% of expense
2003	12.569194114071555
2004	11.5613262515453
2005	10.03287210532374
2006	9.551183964696634
2007	8.051290711292225
2008	7.704456538596395
2009	7.220949430209386
2010	6.686317117730345
2011	5.915747858322005
2012	6.159278329403
2013	6.757306886580153
2014	7.383734283864669
2015	7.771018643963711
2016	9.082790528278776
2017	8.664579235699836
2018	9.962579500192408
2019	9.585777133688307
2020	9.064273910422152
2021	9.500352151665938