Year Percent 1999-01-01 62.650 2000-01-01 62.975 2001-01-01 63.250 2002-01-01 62.975 2003-01-01 62.125 2004-01-01 64.975 2005-01-01 66.100 2006-01-01 66.750 2007-01-01 66.575 2008-01-01 67.525 2009-01-01 67.850 2010-01-01 67.375 2011-01-01 66.450 2012-01-01 66.900 2013-01-01 66.600 2014-01-01 67.250 2015-01-01 67.950 2016-01-01 68.600 2017-01-01 71.225