Year Number 2004-01-01 0.6561 2005-01-01 0.9068 2006-01-01 0.8947 2007-01-01 0.7249 2008-01-01 0.6811 2009-01-01 0.6295 2010-01-01 0.6361 2011-01-01 0.8352 2012-01-01 0.8698 2013-01-01 1.3285 2014-01-01 1.9252 2015-01-01 3.4275 2016-01-01 4.4095