Year	Percent
1990	19.6
1991	23
1992	23.5
1993	23.9
1994	24.4
1995	24.9
1996	24.1
1999	29.6
2000	29.6
2001	18.4
2003	17.92
2005	14.93
2008	16.15
2009	12.59