Year Number 2004-01-01 15.0849 2005-01-01 15.7842 2006-01-01 15.9840 2007-01-01 16.8831 2008-01-01 17.4825 2009-01-01 18.1818 2010-01-01 18.3816 2011-01-01 21.6783 2012-01-01 21.6783 2013-01-01 30.9690 2014-01-01 33.3666 2015-01-01 34.4655 2016-01-01 40.1598