Year	% of expense
2013	2.364391087225035
2014	2.5285013419883042
2015	3.442561601730587
2016	5.670082281714772
2017	5.7254095039493444
2018	6.545908796266228
2019	7.5031476572440745
2020	8.102103348542153
2021	3.6620129774277332
2022	4.743916459272429