Year Percent 2000-01-01 91.775 2001-01-01 91.300 2002-01-01 91.300 2003-01-01 91.275 2004-01-01 90.975 2005-01-01 91.075 2006-01-01 91.675 2007-01-01 91.600 2008-01-01 91.650 2009-01-01 91.625 2010-01-01 91.425 2011-01-01 91.650 2012-01-01 92.000 2013-01-01 92.025 2014-01-01 92.225 2015-01-01 91.925 2016-01-01 92.175 2017-01-01 92.350