Year	% of expense
1995	10.767433180246993
1996	11.213384052528287
1997	13.035103080474409
1998	12.489723966675989
1999	12.355047372065952
2000	11.86418965017437
2001	10.811461043356513
2002	10.835484405711986
2003	11.318619128466327
2004	10.217810524888549
2005	8.527491118377597
2006	7.606861561869025
2007	7.010277519858285
2008	6.4044289044289044
2009	7.212575710347948
2010	6.59140655359092
2011	6.435592436427645
2012	6.30286484015348
2013	6.491450382140117
2014	7.383734283864669
2015	7.374210737495614
2016	8.644827317562493
2017	8.04364090674932
2018	9.432469162936544
2019	8.948125685752123
2020	7.987768322151054
2021	7.331917287862824
2022	7.619972328377171