Year	% of expense
2003	15.836085259681779
2004	15.289814293753517
2005	13.745829864422197
2006	14.31679180580256
2007	14.222316409520444
2008	13.352438224647878
2009	14.175860963992514
2010	15.695578236781426
2011	17.537803707577297
2012	17.254830284571955
2013	17.99719405663763
2014	20.527169549312855
2015	19.948635334830612
2016	22.52979904778969