Year	% of expense
1990	10.050397754461237
1991	9.937339797218309
1992	9.544415719412164
1993	8.914964447345824
1994	8.844836482234092
1995	8.549594308644789
1996	8.183429614504151
1997	7.919499512369063
1998	8.447823250941259
1999	14.421705399267443
2000	16.008276742877715
2001	11.24726586728874
2002	16.55328436204398
2003	8.951039164996889
2004	9.629831889764372
2005	9.229922362681057
2006	9.039479994107385
2007	10.13729211347524
2008	10.221797790831454
2009	8.844875817254565
2010	9.383305640579879
2011	9.962182329541056
2012	8.809646502164274
2013	9.284865342112742
2014	9.190963820564765
2015	9.402638031073282
2016	10.11885412267864
2017	9.5681256814693
2018	9.733954832402935
2019	9.999323673815226
2020	9.184946055503502
2021	9.354033235629364
2022	10.17042998565299