Year Number 2008-01-01 4.7326 2009-01-01 171.5223 2010-01-01 422.5258 2011-01-01 813.7033 2012-01-01 1000.7606 2013-01-01 1149.3510 2014-01-01 1447.7171 2015-01-01 1823.3538