Year Percent 1996-01-01 69.9519 1997-01-01 67.3617 1998-01-01 71.9591 1999-01-01 77.8894 2000-01-01 77.7024 2001-01-01 83.0747 2002-01-01 72.3688 2003-01-01 81.7076 2004-01-01 77.9145 2005-01-01 63.5469 2006-01-01 68.9244 2007-01-01 69.4395 2008-01-01 95.0808 2009-01-01 81.6062 2010-01-01 83.1963 2011-01-01 83.5292 2012-01-01 72.8381 2013-01-01 79.4357 2014-01-01 79.3187