Year Number 2004-01-01 2.0008 2005-01-01 2.2835 2006-01-01 3.0667 2007-01-01 2.8449 2008-01-01 3.1409 2009-01-01 3.5536 2010-01-01 5.4952 2011-01-01 6.0530 2012-01-01 11.0116 2013-01-01 11.2990 2014-01-01 12.5256 2015-01-01 14.4619