Year	% of expense
1990	0.40357345954176066
1991	0.3671144475174503
1992	0.9521057354484479
1993	1.4449644557846335
1994	0.8309501969459883
1995	13.649160227880088
1996	13.977759007933019
1997	13.689835754605856
1998	14.125111709096497
1999	14.123994447105037
2000	14.475492606839198
2001	13.76933235122005
2002	13.482526254108643
2003	14.114625915662982
2004	14.341644121157138
2005	14.527630152179203
2006	13.716215336316493
2007	12.774675122716395
2008	12.220553166545436
2009	12.378923894006112
2010	11.826386966749027
2011	11.522412202129598
2012	11.598427861214503
2013	11.266240167835525
2014	11.226411086599645
2015	11.080936774376388
2016	11.209422587865292
2017	11.32659100570396
2018	11.608536234052046
2019	11.79031243500449
2020	12.057750023982567
2021	12.194258143896116
2022	13.737311121360477