Year Number 2004-01-01 27.7497 2005-01-01 18.5207 2006-01-01 17.8506 2007-01-01 11.5381 2008-01-01 12.6780 2009-01-01 13.1446 2010-01-01 13.2362 2011-01-01 19.7290 2012-01-01 17.1924 2013-01-01 16.9031 2014-01-01 17.6949 2015-01-01 17.5486 2016-01-01 16.7073