Year Number 2007-01-01 474.0042 2008-01-01 492.9766 2009-01-01 483.6212 2010-01-01 485.0326 2011-01-01 504.9538 2012-01-01 533.3203 2013-01-01 574.6674 2014-01-01 564.7417 2015-01-01 577.5904 2016-01-01 600.4058 2017-01-01 612.4484