Year	% of expense
1990	0.6760861470928295
1991	1.0224507303636352
1992	7.388730140587496
1993	11.922632047686093
1994	10.820162309245768
1995	14.416562660597606
1996	11.308341229330319
1997	16.93615004834692
1998	7.949880953016955
1999	20.36880704176165
2000	12.101999090769855
2001	7.561070182241179
2002	3.971362202898553
2003	2.84170983872919
2004	3.166434138169423
2005	5.272226050999311
2006	6.6394540798102755
2007	5.796371085209366
2008	6.611142062963431
2009	5.86437165959417
2010	5.458676451440757
2011	5.802132120981133
2012	7.603791740461416
2013	7.5439802713785475
2014	8.010360960901453
2015	7.495568758693589
2016	7.666992951332562
2017	7.695211136987059
2018	7.289757310016533
2019	7.003508233059481
2020	6.691243036056012
2021	5.656342057212912
2022	10.182482714871199