Year	Percent
1995	83.96
1996	83.94
1997	82.97
1998	81.56
1999	81.66
2000	81.75
2001	82.06
2002	83.51
2003	82.89
2004	81.92
2005	82.35
2006	80.59
2007	80.16
2008	76.39
2009	78.78
2010	80.13