Year	% of expense
2005	28.87357311312222
2006	25.072347091973278
2007	8.042895442359251
2008	18.281516619060316
2009	21.544790378930294
2010	15.906830886817827
2011	16.02784459301383
2012	17.50129071284415
2013	20.34001430214306
2014	21.030787404397884
2015	22.590205039151524
2016	22.640504971314797
2017	22.400655217540056
2018	27.386915085376945
2019	28.338827438985128
2020	28.46499904851079
2021	23.633460526504777