Year Number 2004-01-01 7.9491 2005-01-01 13.3269 2006-01-01 21.1095 2007-01-01 52.7534 2008-01-01 236.4654 2009-01-01 253.5177 2010-01-01 266.9895 2011-01-01 281.5970 2012-01-01 287.0004 2013-01-01 296.3848 2014-01-01 308.1779 2015-01-01 318.7065 2016-01-01 316.5577