Year	% of expense
2010	27.647716294775883
2011	27.365877514001497
2012	27.10748804181666
2013	26.698872557342323
2014	27.81810683499068
2015	26.11413314571227
2016	24.05700478029334
2017	22.9139379985175
2018	15.996655007614837
2019	11.933206204217948
2020	15.027405836890747
2021	14.077748717354277