Year	% of expense
1994	18.29389467486108
1995	22.75619903655616
1996	22.49666761746991
1997	17.932432246115383
1998	16.629756342448747
1999	17.5382941471073
2000	18.871736882769934
2001	20.02129178297409
2002	19.759119142463497
2003	21.445305825871607
2004	18.615354777108077
2005	18.523148630248034
2006	17.816302428322338
2007	21.325761484315738
2008	20.398158441967578
2009	16.82262831316411
2010	14.092328223138628
2011	15.322592403157332
2012	15.520206627060807
2013	16.072946374407792
2014	16.42543250517624
2015	16.99039738773861
2016	17.893478486390453
2017	18.574789646886952
2018	18.617436978294517
2019	18.60872412922873
2020	17.569399716235328
2021	16.890997448016602
2022	17.11692054260909