Year Number 2004-01-01 4.6338 2005-01-01 5.3101 2006-01-01 6.3606 2007-01-01 7.7277 2008-01-01 9.8863 2009-01-01 9.3251 2010-01-01 9.4834 2011-01-01 10.4475 2012-01-01 12.2751 2013-01-01 14.3474 2014-01-01 14.1027 2015-01-01 13.9732 2016-01-01 14.1747