Year	% of expense
2010	34.31484620762713
2012	35.96444097924468
2014	36.208861697212285
2015	35.07464469307314
2016	37.30723302762344
2017	39.14937525380557
2018	37.62991407551451
2019	39.59130977327702
2020	36.000985586672925
2021	33.976267148518275