Year Number 2007-01-01 2.9946 2008-01-01 3.0099 2009-01-01 2.9823 2010-01-01 2.9581 2011-01-01 2.9744 2012-01-01 2.8926 2013-01-01 2.9640 2014-01-01 3.0842 2015-01-01 3.0347 2016-01-01 3.3612