Year Percent 2000-01-01 76.475 2001-01-01 76.250 2002-01-01 75.775 2003-01-01 75.750 2004-01-01 76.000 2005-01-01 76.425 2006-01-01 75.400 2007-01-01 75.600 2008-01-01 76.275 2009-01-01 77.450 2010-01-01 78.575 2011-01-01 78.675 2012-01-01 79.125 2013-01-01 79.100 2014-01-01 79.650 2015-01-01 79.575 2016-01-01 78.975 2017-01-01 78.750