Year	% of expense
1993	11.235929565588926
1994	11.266449409669846
1995	11.86773162073829
1996	13.017022763931038
1997	13.2426229994954
1998	12.710866042707169
1999	12.740685003085023
2000	13.405330538628888
2001	13.942197662381261
2002	14.791498748700544
2003	15.236036619197337
2004	15.223532307656875
2005	15.487145022691992
2006	15.620267010714088
2007	15.506928940318902
2008	16.319142538312523
2009	15.77488447336947
2010	14.35883323312106
2011	14.890856720696267
2012	14.56866238675679
2013	15.099303829078584
2014	14.988115679130726
2015	14.384191921029124
2016	14.705600848874717
2017	15.14433059485124
2018	15.66184261738988
2019	15.811081584577597
2020	15.070637141253297
2021	15.130019044261617
2022	15.623502430814709