Year Number 2004-01-01 11.3696 2005-01-01 8.4865 2006-01-01 11.4027 2007-01-01 15.3596 2008-01-01 18.9063 2009-01-01 20.7724 2010-01-01 22.3394 2011-01-01 26.3465 2012-01-01 31.3776 2013-01-01 36.6752 2014-01-01 45.6804 2015-01-01 42.7713