Year	% of expense
1990	1.5254012468497118
1991	1.9134049015629422
1992	0.5061311379261653
1993	1.1041337436579903
1995	5.255133641431226
1996	5.110387896912657
1997	4.994002399040384
1998	4.494848212433442
1999	4.131068120069396
2000	4.0296956198960645
2001	3.6050325286305718
2002	3.7058124566788795
2003	3.544007196803281
2004	4.436240392180597
2005	4.259509135334233
2006	4.435836347119619
2007	4.567203827873706
2008	4.934357481517776
2009	3.8459427567849405
2010	5.107920309059504
2011	5.556113734552396
2012	5.66340426061111
2013	5.501067214896486
2014	4.74439304327458
2015	14.078752483405848
2016	11.021247254046214
2017	11.696218850554402
2018	19.364298189912642
2019	14.444161939812403
2020	9.315566355543368
2021	9.55677514661133
2022	10.55269466697691