Year	% of expense
2010	20.222626326420613
2012	23.2019425710465
2013	18.273983141844923
2014	21.20136894966287
2015	19.897246911456392
2016	21.605766389454715
2017	26.04515408231107
2018	22.892407035782973
2019	22.271984131606448
2020	17.342391313225903
2021	20.176286574547458