Year Number 2004-01-01 0.3856 2005-01-01 0.9500 2006-01-01 0.7392 2007-01-01 1.0950 2008-01-01 1.4325 2009-01-01 2.9433 2010-01-01 5.9702 2011-01-01 8.9564 2012-01-01 10.2622 2013-01-01 14.6140 2014-01-01 34.1729 2015-01-01 35.1530 2016-01-01 29.1019 2017-01-01 20.1396