Year Percent 2000-01-01 50.725 2001-01-01 52.250 2002-01-01 53.425 2003-01-01 55.350 2004-01-01 56.150 2005-01-01 56.825 2006-01-01 57.300 2007-01-01 57.375 2008-01-01 57.950 2009-01-01 57.525 2010-01-01 57.150 2011-01-01 56.675 2012-01-01 58.075 2013-01-01 59.775 2014-01-01 60.950 2015-01-01 62.200 2016-01-01 63.375 2017-01-01 64.050