Year Percent 2006-01-01 71.300 2007-01-01 71.850 2008-01-01 71.275 2009-01-01 70.100 2010-01-01 68.875 2011-01-01 67.225 2012-01-01 66.875 2013-01-01 67.000 2014-01-01 66.600 2015-01-01 65.900 2016-01-01 64.350 2017-01-01 63.175