Year Number 2006-01-01 6.7408 2007-01-01 7.1256 2008-01-01 6.8473 2009-01-01 7.2158 2010-01-01 4.8560 2011-01-01 3.9331 2012-01-01 4.3459 2013-01-01 4.2472 2014-01-01 5.2356 2015-01-01 6.1509 2016-01-01 6.0101