Year Percent 1999-01-01 65.400 2000-01-01 65.575 2001-01-01 65.150 2002-01-01 65.150 2003-01-01 64.900 2004-01-01 65.400 2005-01-01 66.000 2006-01-01 65.700 2007-01-01 66.125 2008-01-01 65.950 2009-01-01 65.550 2010-01-01 66.025 2011-01-01 64.925 2012-01-01 64.975 2013-01-01 64.975 2014-01-01 64.650 2015-01-01 64.275 2016-01-01 64.125 2017-01-01 64.350