Year Number 2004-01-01 306.1304 2005-01-01 287.3750 2006-01-01 263.8694 2007-01-01 261.5803 2008-01-01 307.5698 2009-01-01 301.7121 2010-01-01 294.4179 2011-01-01 287.3291 2012-01-01 303.3545 2013-01-01 250.7087 2014-01-01 452.0774 2015-01-01 484.8027 2016-01-01 509.8353