Year Percent 2003-01-01 87.025 2004-01-01 86.825 2005-01-01 88.850 2006-01-01 88.700 2007-01-01 89.275 2008-01-01 88.400 2009-01-01 84.225 2010-01-01 83.225 2011-01-01 82.025 2012-01-01 83.150 2013-01-01 87.150 2014-01-01 88.725 2015-01-01 88.925 2016-01-01 89.675 2017-01-01 89.075