Year	% of expense
1996	14.466469843947701
1997	15.188604369438991
1998	12.16900107095609
1999	15.105378036998603
2000	14.684891656018054
2001	18.059590778993247
2002	16.637876304793963
2003	18.923495861162667
2004	18.57750773457831
2005	18.70585910277613
2006	19.786358009942564
2007	19.59521561083614
2008	16.72385126030856
2009	17.070949390113057
2010	15.919023223016138
2011	16.088914942201097
2012	15.685809033065754
2013	16.134903747345746
2014	15.730450254792064
2015	16.89596248694593
2016	14.35360950897953
2017	15.995164583692265
2018	15.30611307524103
2019	11.999167524551984
2020	11.191390778531074
2021	9.32725088598405
2022	10.80010833730259