Year	% of expense
2010	30.49062549091075
2012	25.951386060323816
2013	27.260924051803244
2014	26.670298607740012
2015	25.203367165843908
2016	25.056355012460806
2017	20.215257949934255
2018	20.39906115709516
2019	23.34083003281196
2020	26.093700683850336
2021	25.40714350109469