Year Percent 2000 92.1 2001 91.59 2002 91.08 2003 90.57 2004 90.06 2005 89.55 2006 89.04 2007 88.53 2008 88.02 2009 87.51 2010 87 2011 86.49 2012 85.98 2013 85.98 2014 85.98 2015 85.98