Year	% of expense
2012	6.08845532244819
2013	10.689966353250156
2014	8.085182245457517
2015	11.785907743515228
2016	13.604628992014334
2017	16.12477918390559
2018	17.536026020986448
2019	16.79740393814069
2020	20.446329520928302
2021	20.36149089652194