Year	% of expense
1990	5.7915057915057915
1991	8.798531695609205
1992	7.418350656888091
1993	7.494543971988392
1994	7.159124219260862
1995	7.215195105820106
1996	7.484508677012935
1997	2.270913569966344
1998	2.8195427943221136
1999	5.051055741376516
2004	10.80832700683262
2005	10.504397380750158
2006	9.52582235034534
2007	9.682313456852558
2008	10.880993683541455
2009	12.246893660194234
2010	11.729913427991427
2011	10.429348776909999
2012	9.289341525685266