Year Percent 1995 77.17 1996 76.68 1997 77.29 1998 77.03 1999 77.48 2000 78.02 2001 76.42 2002 77.9 2003 78.34 2004 79.63 2005 79.68 2006 80.07 2007 82.4 2008 82.84 2009 83.03 2010 83.22