Year Number 2004-01-01 27.1392 2005-01-01 27.4151 2006-01-01 28.2798 2007-01-01 38.8308 2008-01-01 41.5919 2009-01-01 52.0680 2010-01-01 53.7014 2011-01-01 53.5897 2012-01-01 53.0250 2013-01-01 54.1474 2014-01-01 51.6732 2015-01-01 50.4306 2016-01-01 48.1060