Year	% of expense
1972	5.596738324684951
1973	5.600696459663378
1974	2.7382680212868893
1975	2.7609147609147606
1976	1.9117751186008638
1977	2.4077450179166404
1978	0.5778910085130181
1979	2.2428320300660727
1980	1.9105867070794547
1981	0.9561279107003979
1982	0.6826357096141269
1983	0.3788698852565491
1984	0.22777396145919954
1985	0.33109156751163993
1986	0.16476234822164118
1987	0.1255512003919647
1988	0.1144677250783855
1989	0.07591155079952004
1990	0.05384449709239716
1991	0.042241622078287806
1992	0.03005108684764099
1993	0.0952925481227368
1994	0.08750921149594694
1995	0.02383952593399857
1996	0.028425914959137745
1997	0.17257453434629955
1998	0.7239382239382239
1999	7.36464449081393E-05
2000	7.659309423386251E-05
2001	8.877162457476462E-05
2002	0.9744787360046483
2003	1.0274871199679023
2004	1.0095243029486143
2005	1.0815482885930288
2006	1.0776033770047533
2007	1.4159457200342742
2008	1.1238268991061742
2009	0.7310571919875923