Year	% of expense
1993	8.413530207879669
1994	8.521805818832807
1995	7.518153743427093
1996	7.958875536892659
1997	9.383965540476753
1998	9.08585137541763
1999	7.745346616924342
2000	7.570082099627758
2001	7.186494869622873
2002	6.377267350088768
2003	5.7582656664441
2004	5.188192403631553
2005	4.486980722775975
2006	4.156903961142204
2007	3.832233340430062
2008	3.4986157777099
2009	3.39021003341972
2010	3.824796305876024
2011	4.257466342536468
2012	4.4988847769506535
2013	4.617936718119271
2014	4.541002799337841
2015	4.262201616981294
2016	4.273063120379516
2017	4.096380980067511
2018	4.037418464096025
2019	3.7167029714455326
2020	3.435597311253268
2021	3.1347648593141244
2022	3.210085911324631