Year Percent 1995-01-01 46.71 1996-01-01 51.99 1997-01-01 58.76 1998-01-01 65.35 1999-01-01 78.63 2000-01-01 77.16 2001-01-01 73.53 2002-01-01 65.23 2003-01-01 70.00 2004-01-01 70.81 2005-01-01 80.25 2006-01-01 81.46 2007-01-01 79.70 2008-01-01 72.01 2009-01-01 87.36 2010-01-01 85.57 2011-01-01 81.70 2012-01-01 86.84 2013-01-01 93.59 2014-01-01 101.56 2015-01-01 97.42