Year	% of expense
2010	27.26322933209034
2012	23.382884068817084
2013	23.247325694706007
2014	23.980864823237148
2015	23.175765227573986
2016	23.956602929281846
2017	21.68653105116946
2018	18.995965954538946
2019	22.571468348672315
2020	28.648242550877427
