Year Number 2007-01-01 588.9018 2008-01-01 697.4638 2009-01-01 615.2622 2010-01-01 555.8599 2011-01-01 492.0544 2012-01-01 490.4345 2013-01-01 465.2251 2014-01-01 475.3789 2015-01-01 503.1785 2016-01-01 496.0439 2017-01-01 510.7758