Year Percent 2000-01-01 45.800 2001-01-01 46.200 2002-01-01 46.775 2003-01-01 47.775 2004-01-01 48.300 2005-01-01 49.925 2006-01-01 51.725 2007-01-01 52.025 2008-01-01 51.950 2009-01-01 49.050 2010-01-01 47.325 2011-01-01 49.225 2012-01-01 50.350 2013-01-01 50.875 2014-01-01 50.875 2015-01-01 52.500 2016-01-01 52.950 2017-01-01 54.050