Year Number 2008-01-01 406.4334 2009-01-01 404.8267 2010-01-01 388.0130 2011-01-01 367.5795 2012-01-01 368.1658 2013-01-01 353.6038 2014-01-01 339.3245 2015-01-01 340.0826 2016-01-01 340.6346 2017-01-01 343.3360