Year	% of expense
1974	10.937499999999996
1975	10.757745427398289
1976	10.105633802816904
1977	9.925586396174642
1978	8.962962962962953
1979	9.439718934911252
1980	10.279123050449714
1981	10.419518204215688
1982	10.30686038178383
1983	10.199377665091607
1984	10.13467856560337
1985	10.135759817040542
1986	9.49109400587509
1987	9.87046724860441
1988	10.002432556620663
1989	9.80842076451398
1990	10.003932519146282
1991	8.283832645823
1992	8.960503683510199
1993	9.280638411638305
1994	10.146595034654732
1995	6.758072876481568
1996	6.921527330776701
1997	7.217231964094858
1998	7.137733399646513
1999	7.261869679948687
2000	7.3945760185267275
2001	7.938513993519876
2002	8.474137010059907
2003	8.052140872560084
2004	8.790630832463737
2005	9.177272893038182
2006	10.301150095127094
2007	10.400864512062686
2008	9.943798689431071
2009	9.115310964583939
2010	8.52239584636059
2011	7.986139989026254
2012	8.037289569396659
2013	7.86447800309738
2014	7.590605612378816
2015	7.84386526907525
2016	8.223283966639155
2017	8.141101838043323
2018	7.782725145575231
2019	7.669129094891169
2020	7.325676731704852
2021	7.882223251210226
2022	8.423964735696817