Year Number 2004-01-01 45.3866 2005-01-01 45.1517 2006-01-01 41.3555 2007-01-01 46.8226 2008-01-01 47.4137 2009-01-01 48.8194 2010-01-01 52.3205 2011-01-01 55.3747 2012-01-01 60.4263 2013-01-01 59.1951 2014-01-01 56.3692 2015-01-01 57.0847 2016-01-01 57.4880 2017-01-01 58.8249