Year Percent 2000-01-01 56.875 2001-01-01 55.075 2002-01-01 52.875 2003-01-01 52.450 2004-01-01 53.150 2005-01-01 54.800 2006-01-01 56.600 2007-01-01 59.150 2008-01-01 61.750 2009-01-01 61.675 2010-01-01 60.875 2011-01-01 61.450 2012-01-01 61.550 2013-01-01 61.625 2014-01-01 62.750 2015-01-01 63.500 2016-01-01 64.750 2017-01-01 66.000