Year	Percent
1995	63.86
1996	63.83
1997	57.7
1998	59.18
1999	60.13
2000	60.98
2001	60.06
2002	60.32
2003	62.35
2004	61.22
2005	65.1
2006	63.51
2007	65.61
2008	68.34
2009	67.05
2010	65.7