Year	Percent
1995	52.41
1996	52.08
1997	49.71
1998	50.73
1999	42.73
2000	41.49
2001	37.65
2002	36.73
2003	37.1
2004	42.17
2005	45.29
2006	50.22
2007	51.17
2008	52.68
2009	49.76
2010	49.77