Year Number 2007-01-01 7.7917 2008-01-01 10.2773 2009-01-01 15.5735 2010-01-01 16.4183 2011-01-01 16.7603 2012-01-01 20.6975 2013-01-01 19.4976 2014-01-01 25.0254 2015-01-01 27.1412