Year	% of expense
2005	2.9394403732463963
2006	3.1723140200790123
2007	2.6715899930466596
2008	2.0875080865298137
2009	1.8816376789287363
2010	2.412495724546802
2011	2.580112838124122
2012	3.075508998198172
2013	3.2485984068569924
2014	3.400999880800067
2015	4.011897368653407
2016	4.158080511879058
2017	4.847172454520314
2018	4.180323231578963
2019	3.9397854054038604
2020	3.435597311253268
2021	3.7370126932157515