Year	% of expense
1990	5.856665810428975
2009	11.963532248342375
2010	12.710389240778614
2011	14.37363510025809
2012	13.96928802913537
2013	12.398606865887903
2014	13.18003593318264
2015	15.697629642385225
2016	21.96823706927562
2017	19.789375640834983
2018	14.193618199286085
2019	11.134985745794035
2020	20.916136112930953
2021	16.33050958801194