Year	% of expense
1990	6.11764705882353
1991	0.15199878400972794
1992	2.0093023255813955
1993	4.388164493480441
1994	6.311688311688311
1995	6.824216675517791
1996	5.026656511805026
1997	6.287339971550498
1998	7.669295621430513
2001	10.891514500537056
2002	11.916666666666668
2003	12.632164718976071
2004	12.979446512380644
2005	20.662999851345326
2006	20.485122262594523