Year Percent 2000-01-01 53.450 2001-01-01 53.425 2002-01-01 52.500 2003-01-01 51.825 2004-01-01 51.775 2005-01-01 51.875 2006-01-01 50.750 2007-01-01 50.600 2008-01-01 51.125 2009-01-01 52.025 2010-01-01 52.550 2011-01-01 52.850 2012-01-01 53.375 2013-01-01 53.475 2014-01-01 53.975 2015-01-01 53.925 2016-01-01 54.025 2017-01-01 54.075