Year	% of expense
2010	34.33306058217143
2012	35.37141702918497
2013	34.82701849380899
2014	33.58139056892346
2015	35.07464469307314
2016	37.30723302762344
2017	39.14937525380557
2018	37.62991407551451
2019	40.150610364928276
2020	38.73348578973099