Year Number 2004-01-01 7.5641 2005-01-01 7.5001 2006-01-01 8.9266 2007-01-01 9.9869 2008-01-01 10.9879 2009-01-01 11.6000 2010-01-01 13.9606 2011-01-01 13.1075 2012-01-01 13.2910 2013-01-01 10.9123 2014-01-01 9.9541 2015-01-01 9.7300