Year	% of expense
1990	1.5551643192488263
1991	1.116019530341781
1992	1.7741637405285529
1993	0.9768804949527841
1994	1.1562364503540974
1995	1.560186766883043
1996	3.0563114925685575
1997	2.182741116751269
1998	2.149626319439094
1999	1.6175994823681656
2000	1.5086092009168932
2001	1.5268337222278585
2002	1.5691665876552574
2003	1.5261968708701028
2004	1.7467092285068684
2005	4.8995326599616655
2006	2.6712792895609687
2007	2.5655096721086568
2008	6.420838246328653
2009	4.810094809980718
2010	7.579406983780449
2011	10.984224106623
2014	25.58036801599614
2015	21.33703217707819
2016	21.736024257235552
2017	19.013944035000062
2018	24.467877422985357
2019	19.55990973334667
2020	26.881835385470804
2021	28.71135169460312