Year	% of expense
2012	4.072274161285623
2014	4.105678854867515
2015	5.269708202084798
2016	4.077351475398604
2017	3.9647760722190375
2018	5.0804703798179505
2019	4.2700839546808265
2020	6.001869944825865
2021	4.552089633642274