Year Number 2004-01-01 57.3580 2005-01-01 56.7961 2006-01-01 55.6206 2007-01-01 55.2788 2008-01-01 53.9507 2009-01-01 52.6770 2010-01-01 51.7665 2011-01-01 50.2414 2012-01-01 48.8792 2013-01-01 47.4440 2014-01-01 46.0252 2015-01-01 44.3477 2016-01-01 42.4637