Year Number 2004-01-01 0.2664 2005-01-01 0.3141 2006-01-01 0.4023 2007-01-01 0.5234 2008-01-01 0.6742 2009-01-01 0.8180 2010-01-01 0.8898 2011-01-01 1.0117 2012-01-01 1.1625 2013-01-01 1.2734 2014-01-01 1.3398 2015-01-01 1.3422 2016-01-01 1.4063 2017-01-01 1.4867