Year	% of expense
1990	3.491863912406616
1991	2.685266272495971
1992	16.11921450255743
1993	14.575318835663401
1994	8.077430841835314
1995	5.545692956945098
1996	1.2233457326976476
1997	0.3501800237041489
1998	1.1943062522270647
1999	0.05678240532517766
2000	21.27808285740098
2001	20.411518217088062
2002	3.500317216548828
2003	16.388490165231794
2004	15.196778307202186
2005	27.51908239468581
2006	17.505141194763503
2007	16.244637101596833
2008	9.801964443287188
2009	12.153732560524725
2010	12.495276813345498
2011	10.971272783577115
2012	9.58954887674402
2013	9.274083429913077
2014	4.348103337363082
2015	4.3246917971407
2016	4.796103007303448
2017	4.956701354069168
2018	6.028470312839052
2019	6.457367684737873
2020	6.283967080983084
2021	5.946872624477808
2022	7.22336952471208