Year Number 2004-01-01 0.6561 2005-01-01 0.9078 2006-01-01 0.8958 2007-01-01 0.7262 2008-01-01 0.6825 2009-01-01 0.6310 2010-01-01 0.6376 2011-01-01 0.8363 2012-01-01 0.8698 2013-01-01 1.3309 2014-01-01 1.9280 2015-01-01 3.4322 2016-01-01 4.4263