Year	Percent
1995	42.81
1996	40.06
1997	43.52
1998	41.45
1999	39.83
2000	43.38
2001	45.45
2002	44.64
2003	49.48
2004	44.35
2005	46.95
2006	58.88
2007	64.14
2008	61.7
2009	66.14
2010	67.32