Year	% of expense
1972	9.805194805194798
1973	9.869753979739498
1974	8.616249121985478
1975	8.471313053523307
1976	8.231202384895663
1977	7.439219682632128
1978	7.127725856697806
1979	7.279982743744602
1980	10.595965204515993
1981	10.450630575207667
1982	10.30686038178383
1983	10.199377665091607
1984	10.101328293169527
1985	10.135759817040542
1986	9.212338198843312
1987	9.4510870065754
1988	9.788530413917947
1989	9.321299069840771
1990	9.165211576327208
1991	9.020152883947178
1992	8.960503683510199
1993	9.12918777079392
1994	8.593795985637758
1995	6.758072876481568
1996	6.917024381675761
1997	6.798251516044167
1998	5.8998069932805
1999	5.813849530570435
2000	5.843844390723766
2001	5.624479648097782
2002	5.717372675936925
2003	5.521915235299927
2004	5.721740083448857
2005	5.750876571979317
2006	5.625645410826382
2007	5.5989516628769564
2008	5.499153054773293
2009	5.580617900352582
2010	5.339373216127076
2011	5.440292099466882
2012	5.471050659213061
2013	5.475354042854674
2014	5.291530736631269
2015	5.400244670490915
2016	5.371373186509034
2017	5.4656881723871775
2018	5.524508282822107
2019	5.623664748636554
2020	5.520981427527903
2021	5.705167111555337
2022	5.778850294205914