Year Number 2004-01-01 1.4754 2005-01-01 2.7694 2006-01-01 4.3545 2007-01-01 13.0677 2008-01-01 11.8898 2009-01-01 17.2821 2010-01-01 18.3911 2012-01-01 37.6733 2013-01-01 37.4412 2014-01-01 37.2882 2015-01-01 32.9882 2016-01-01 24.4350