Year Number 2004-01-01 2.7371 2005-01-01 3.6801 2006-01-01 3.4226 2007-01-01 3.7875 2008-01-01 3.1273 2009-01-01 4.1215 2010-01-01 4.3219 2011-01-01 5.5491 2012-01-01 11.4690 2013-01-01 12.0035 2014-01-01 12.8118 2015-01-01 5.1654 2016-01-01 5.2601