Year Percent 1995 59.11 1996 61.89 1997 60.59 1998 66.09 1999 69.98 2000 72.28 2001 73.85 2002 77.26 2003 79.38 2004 77.38 2005 78.71 2006 76.22 2007 76.13 2008 74.74 2009 78.22 2010 78.55