Year Percent 2005-01-01 92.825 2006-01-01 92.925 2007-01-01 92.925 2008-01-01 92.900 2009-01-01 92.500 2010-01-01 92.350 2011-01-01 92.175 2012-01-01 92.175 2013-01-01 91.825 2014-01-01 91.525 2015-01-01 91.425 2016-01-01 91.375 2017-01-01 91.375