Year Percent 1982 69.5 1985 74 1988 71.1 1992 84.6 1994 90.7 1995 90.4 1996 91.1 1997 83.8 1999 83 2000 83.8 2001 86.9 2006 84.6 2008 89.3 2009 89 2010 89.1 2011 88.6 2012 87.9