Year Number 2004-01-01 2.0008 2005-01-01 2.2835 2006-01-01 2.3280 2007-01-01 2.0832 2008-01-01 2.1570 2009-01-01 2.2640 2010-01-01 4.2601 2011-01-01 4.7163 2012-01-01 9.7001 2013-01-01 10.5843 2014-01-01 11.1588 2015-01-01 13.8556