Year Percent 2005-01-01 59.875 2006-01-01 60.375 2007-01-01 60.900 2008-01-01 60.725 2009-01-01 58.675 2010-01-01 57.975 2011-01-01 57.775 2012-01-01 56.975 2013-01-01 56.225 2014-01-01 56.225 2015-01-01 56.525 2016-01-01 57.275 2017-01-01 57.925