Year	% of expense
2012	35.96444097924468
2014	31.40878914190632
2015	32.738770805141634
2016	31.350733006680464
2017	29.703134666967912
2018	27.24082234622383
2019	24.916683546223926
2020	28.572617642638278
2021	29.59237516859826