Year	% of expense
2004	41.55259539700635
2005	39.81705244273571
2006	34.77190847772073
2007	36.219116630209825
2008	11.88360131357142
2009	12.719006324611112
2010	13.350657158405685
2011	14.197898258477268
2012	16.368168369708016
2013	15.705602468192312
2014	17.108261592772607
2015	15.916629050277036
2016	10.411086478005767
2017	14.68422000863749
2018	13.913573999226504
2019	14.457250831911624
2020	11.555422283171064
2021	11.920063138432166
2022	12.036671587701548