Year	Percent
1990	16.71201
1991	18.0897
1992	19.39617
1993	17.46057
1994	17.46983
1995	18.62901
1996	15.64275
1998	15.97697
1999	18.10859
2000	15.42475
2001	19.00545
2002	18.05816
2003	18.82293
2004	16.40245
2005	13.8244
2006	14.58074
2007	14.19468