Year Percent 2000-01-01 45.300 2001-01-01 46.800 2002-01-01 48.025 2003-01-01 48.975 2004-01-01 49.500 2005-01-01 51.600 2006-01-01 53.125 2007-01-01 53.900 2008-01-01 53.800 2009-01-01 51.250 2010-01-01 50.275 2011-01-01 50.125 2012-01-01 49.375 2013-01-01 51.300 2014-01-01 52.975 2015-01-01 55.650 2016-01-01 57.200 2017-01-01 58.650