Year	% of expense
1972	17.200151343170628
1973	16.287522717302682
1974	17.048054919908427
1975	17.351640250645033
1976	17.215200262639456
1977	17.147447873850986
1978	16.568862079139794
1979	16.362035462715554
1980	16.315389593944357
1981	16.371726677577726
1982	16.591854480505756
1983	16.6299775506201
1984	16.51019147621987
1985	16.640231843192534
1986	16.518679234962725
1987	15.959763559058384
1988	15.808481085055956
1989	16.06473540435804
1990	15.707202660174588
1991	15.353587836359658
1992	15.452280469822547
1993	15.421274017454534
1994	15.988611339724605
1995	4.190108989950833
1996	4.20922271239863
1997	4.325774957792015
1998	4.5794196391664075
1999	4.584801038576641
2000	4.4279918176487225
2001	4.683039386064365
2002	4.672132492209802
2003	4.84373830399317
2004	4.46803789258651
2005	6.367055004423847
2006	6.641946107396031
2007	6.320275697529275
2008	6.54903711295408
2009	6.361518779849594
2010	6.641649081636686
2011	6.638937145394983
2012	6.369324263852788
2013	6.282896764824085
2014	5.966773490325396
2015	6.0694889584930545
2016	6.210018539316626
2017	6.1787541903910945
2018	6.281937110523224
2019	6.2449004201637965
2020	5.853524877101612
2021	6.696051870387105
2022	6.862655921272831