Year Number 2007-01-01 490.8010 2008-01-01 516.7238 2009-01-01 505.9601 2010-01-01 507.4033 2011-01-01 527.6327 2012-01-01 559.2678 2013-01-01 601.8743 2014-01-01 589.7489 2015-01-01 602.6149 2016-01-01 625.8090 2017-01-01 638.9302