Year Number 2004-01-01 6.7089 2005-01-01 8.2256 2006-01-01 15.4756 2007-01-01 26.2066 2008-01-01 37.2734 2009-01-01 37.9963 2010-01-01 38.3297 2011-01-01 49.8041 2012-01-01 38.7989 2013-01-01 44.5792 2014-01-01 63.3361 2015-01-01 43.7943