Year Percent 2003-01-01 86.300 2004-01-01 85.750 2005-01-01 86.875 2006-01-01 88.050 2007-01-01 89.125 2008-01-01 87.300 2009-01-01 80.000 2010-01-01 80.100 2011-01-01 80.275 2012-01-01 81.450 2013-01-01 83.175 2014-01-01 85.350 2015-01-01 87.100 2016-01-01 89.400 2017-01-01 88.600