Year Percent 2005-01-01 64.000 2006-01-01 64.700 2007-01-01 65.200 2008-01-01 65.900 2009-01-01 65.400 2010-01-01 63.775 2011-01-01 64.475 2012-01-01 64.500 2013-01-01 64.325 2014-01-01 64.650 2015-01-01 64.875 2016-01-01 65.200 2017-01-01 65.175