Year	% of expense
2010	35.72511665426649
2012	38.09740694622225
2013	36.88479850385897
2014	37.552668790600585
2015	36.75759026095814
2016	36.65405380223012
2017	38.39949816291782
2018	36.86824676432224
2019	39.678734439215
2020	37.924096853244464
2021	34.45318595569239