Year	% of expense
1991	3.678004171346061
1992	3.778215631373363
2000	0.5803202276219005
2001	0.8163385059838161
2002	1.309813346454841
2003	1.4814465029007362
2004	0.6137372072898652
2005	2.725107950864731
2006	1.8788949693230559
2007	0.25171128258354564
2008	1.7340264020192797
2009	1.4058388313560002
2010	0.3230165315990097
2011	1.9875804324760507
2012	1.3944979682385528
2013	0.30483993831427325
2014	0.3682917320178207
2015	0.28153315055540584
2016	0.6178874352395087
2017	0.7519233385226946
2018	2.2102446891146514
2019	2.15817115938714
2020	1.944962460816609
2021	1.6305059296487345
2022	0.75039939272967