Year	% of expense
1986	24.270032930845225
1987	17.965228589826143
1988	21.64025356576862
1989	24.00506512301013
1990	31.38203221243783
1991	32.05137429846021
1992	32.16160989110473
1993	29.64226239441424
1994	27.559445493202144
1995	27.483443708609272
1996	22.967887961522138
1997	15.289296516733339
1998	17.109704870344842
1999	16.414826817905613
2000	16.427125885395196
2001	17.80565306538705
2002	16.231161613667098
2003	16.77759449521945
2004	16.83882171000892
2005	13.822446925521344
2006	13.99083870578022
2007	14.196045244360949