Year	% of expense
2008	17.352626913372465
2009	18.21058549624979
2010	17.901223445467483
2011	17.77701327079297
2012	16.03352865908886
2013	15.891892444730852
2014	15.585006535090642
2015	15.538462058269129
2016	15.329970971214937
2017	15.219294970590528
2018	16.195700711760736
2019	16.203136292242476
2020	15.751653525185205
2021	15.73752614448885
2022	19.136149836376184