Year	% of expense
2003	13.639793404185102
2006	17.799088141720716
2007	18.63353876038203
2008	13.959820810603262
2009	13.086826246830416
2010	13.350657158405685
2011	13.465544990317513
2012	15.685809033065754
2013	14.214415050506538
2014	13.441552218729676
2015	12.98584824886769
2016	12.266532612556832
2017	13.009635329397586
2018	13.12057065640614
2019	12.198159358437884
2020	12.637239646250897
2021	13.787792156267868
2022	13.251325569500723