Year	Percent
1995	24.37
1996	26.93
1997	28.52
1998	29.76
1999	33.8
2000	38.96
2001	38.39
2002	39.22
2003	41.25
2004	39.62
2005	40.76
2006	39.97
2007	35.9
2008	31.86
2009	22.87
2010	25.11