Year	Percent
1990	45.1
1991	45.3
1992	53.6
1993	53.8
1994	53.8
1995	52.4
1996	46.3
1997	56.4
1998	47.3
1999	46.3
2000	57.1
2001	58.9
2002	58
2003	58.33
2004	55.32
2005	55.42
2006	53.01
2007	60.86
2008	59.11
2009	56.94