Year Number 2006-01-01 9.6094 2007-01-01 12.7930 2008-01-01 17.5977 2009-01-01 26.4648 2010-01-01 21.4453 2011-01-01 23.4766 2012-01-01 25.0781 2013-01-01 26.7188 2014-01-01 27.8516 2015-01-01 29.4727 2016-01-01 29.5313 2017-01-01 30.0586