Year Percent 2005-01-01 83.900 2006-01-01 84.700 2007-01-01 85.600 2008-01-01 85.400 2009-01-01 84.400 2010-01-01 83.225 2011-01-01 84.050 2012-01-01 83.900 2013-01-01 83.450 2014-01-01 83.350 2015-01-01 83.575 2016-01-01 83.700 2017-01-01 84.275