Year Percent 1995 81.12 1996 84.25 1997 86.08 1998 89.91 1999 89.48 2000 86.56 2001 88.2 2002 84.76 2003 87.67 2004 86.49 2005 91.02 2006 85.62 2007 88.28 2008 88.97 2009 88.67 2010 87.82