Year Percent 1991-01-01 96.8646 1992-01-01 86.0740 1993-01-01 60.1775 1994-01-01 68.6206 1995-01-01 71.6123 1996-01-01 73.1893 1997-01-01 76.2293 1998-01-01 65.0124 1999-01-01 52.7815 2000-01-01 55.9863 2001-01-01 63.2736 2002-01-01 67.9640 2003-01-01 72.6655 2004-01-01 75.2095 2005-01-01 77.6585 2006-01-01 82.6496 2007-01-01 87.8045 2008-01-01 90.7623 2009-01-01 91.6015 2010-01-01 92.0847 2011-01-01 92.9063 2012-01-01 94.2247 2013-01-01 95.3207 2014-01-01 95.5865 2015-01-01 95.5150 2016-01-01 83.4844