Year	% of expense
2010	2.0208746548128658
2012	4.100669406043811
2014	6.396820642454715
2015	6.008664193651036
2016	4.311617889485698
2017	3.7247429911146783
2018	3.423439757139272
2019	3.8890233587613947
2020	5.974824850691716