Year	% of expense
2000	17.228388175484024
2001	17.713251082996027
2002	21.18813981074796
2003	22.554850435181432
2004	21.599204777473975
2005	20.091530916008672
2006	9.55760068733115
2007	9.425972532912045
2008	20.346944212924143
2009	19.331900942983346
2010	20.050617748110298
2011	21.176647185338478
2012	22.247803127175906
2013	20.294557660822306
2014	21.246067312790217
2015	21.954680601856023
2016	21.94382328879193
2017	24.04659679252431