Year	% of expense
1990	2.3715415019762944
1991	1.1142459197885746
1992	0.7865739955924744
1993	1.3432053466125018
1994	0.9587513935340044
1995	4.4782714164301005
1996	5.142481542770234
1997	5.366054435343911
1998	5.494504932906376
1999	4.998252403161477
2000	5.2504266291241075
2001	6.689415523398506
2002	5.51847282314288
2003	5.195401637263031
2004	5.356343967936177
2005	5.366611391162457
2006	5.704818433849298
2007	4.84397815013706
2008	5.14733760597679
2009	5.716319756493367
2010	5.205118508921154
2011	5.104533438375961
2012	4.903058237318379
2013	5.3765587184216175
2014	4.853675316746855
2015	4.883250127140413
2016	4.82944625765821
2017	4.601475048404045
2018	4.79168537224269
2019	4.814807118669665
2020	4.908329828751924
2021	5.641510625887011
2022	7.192339089922929
