Year	Percent
1996	78.26
1997	78.22
1998	78.62
1999	79.02
2000	81.67
2001	81.47
2002	81.68
2003	82.73
2004	83.08
2005	82.94
2006	82.88
2007	83.58
2008	83.79
2013	70.19