Year Number 2005-01-01 8.3605 2006-01-01 7.6896 2007-01-01 2.1722 2008-01-01 3.0373 2009-01-01 5.1299 2010-01-01 18.4836 2011-01-01 17.0395 2012-01-01 16.6765 2013-01-01 16.2236 2014-01-01 16.9169 2015-01-01 16.5586 2016-01-01 14.6453 2017-01-01 14.5607