Year Number 2004-01-01 0.4035 2005-01-01 0.7397 2006-01-01 0.7397 2007-01-01 0.7397 2008-01-01 0.7397 2009-01-01 0.7397 2010-01-01 0.7397 2011-01-01 1.6812 2012-01-01 1.8830 2013-01-01 2.2192 2014-01-01 2.3537 2015-01-01 2.4210 2016-01-01 2.4210 2017-01-01 2.6227