Year Percent 1990 85.38 1991 85.38 1992 85.38 1993 85.38 1994 85.38 1995 85.38 1996 85.38 1997 85.38 1998 85.38 1999 85.38 2000 85.38 2001 85.38 2002 85.38 2003 85.38 2004 85.38 2005 85.38 2006 85.38 2007 85.38 2008 85.38 2009 85.38 2010 85.38 2011 86.16 2012 86.93 2013 87.71 2014 88.49 2015 89.26