Year Percent 2003-01-01 58.425 2004-01-01 58.025 2005-01-01 57.675 2006-01-01 57.425 2007-01-01 57.650 2008-01-01 57.975 2009-01-01 56.800 2010-01-01 56.650 2011-01-01 56.400 2012-01-01 56.025 2013-01-01 55.375 2014-01-01 54.550 2015-01-01 54.325 2016-01-01 54.400 2017-01-01 54.800