Year	% of expense
1992	2.405498281786942
1993	4.1596873255164715
1994	3.3862672222847916
1995	4.750768772228479
1996	9.93110761802333
1997	8.994236236184095
1998	10.207311883762841
1999	9.165238180611118
2000	10.628121597566667
2001	12.213790084557342
2002	13.73457292524157
2003	12.172623649278535
2004	13.287339489567701
2005	13.45104127388434
2006	12.7610744686705
2007	11.25606456791595
2008	10.137277269121919
2009	10.579600710616232
2010	11.937355304680185
2011	11.673105969047866
2012	11.490100155356494
2013	12.081519358736893
2014	11.973559332384598
2015	12.31445065625113
2016	11.739171693244774
2017	12.981414203514158
2018	14.458611899840523
2019	13.746371669436503
2020	13.199475306336483
2021	13.313618074136402
2022	13.339094165196542