Year	% of expense
1993	8.227402468681113
1994	9.87098295412595
1995	9.402605458234868
1996	12.569106473161254
1997	13.331154473002618
1998	11.710605882830762
1999	13.349686618694765
2000	12.863498670020313
2001	13.036318455812951
2002	13.806153361093513
2003	11.479785117131886
2004	11.931442587996358
2005	12.526841543527393
2006	12.758531125371036
2007	12.518807799701637
2008	12.573556624722428
2009	12.410652940802883
2010	12.126923498155689
2011	11.41698076910881
2012	11.192360236621562
2013	11.797368247316648
2014	11.705844578041411
2015	11.978766474119203
2016	12.404457173259246
2017	13.220644269110245
2018	13.71398210630984
2019	13.727138396046614
2020	12.672146047124738
2021	12.479110552720577
2022	12.124144878247465