Year	% of expense
1990	2.1318904632186615
1991	2.1686720339732823
1992	1.7561247107300733
1993	1.6662129520402007
1994	1.374709348356937
2012	13.710938976006046
2013	5.966063986892468
2014	5.2143559023379975
2015	4.464153484616051
2016	4.5273952856221085
2017	4.630547727954308
2018	5.166646495183307
2019	4.841690096068827
2020	4.410922824087678
2021	6.062880371319976
2022	5.200230893936168