Year	% of expense
2005	5.354611453496521
2006	6.572580079265435
2008	6.611142062963431
2009	9.141279876225969
2010	7.652260962507876
2011	5.802132120981133
2012	6.735202259407941
2013	5.7848037781084445
2014	3.2070576716256785
2015	3.1882614513677696
2016	2.85096920487812
2017	2.9123076167209354
2018	3.1222100400539983
2019	2.600015910617743
2020	3.902812565133015
2021	4.965611338255421