Year Percent 2000-01-01 45.700 2001-01-01 46.600 2002-01-01 47.150 2003-01-01 47.475 2004-01-01 48.150 2005-01-01 49.725 2006-01-01 50.775 2007-01-01 54.175 2008-01-01 53.575 2009-01-01 50.775 2010-01-01 48.925 2011-01-01 48.100 2012-01-01 47.775 2013-01-01 48.425 2014-01-01 48.950 2015-01-01 49.950 2016-01-01 51.400 2017-01-01 52.125