Year Number 2004-01-01 33.6128 2005-01-01 28.0720 2006-01-01 27.6963 2007-01-01 28.6576 2008-01-01 27.5722 2009-01-01 25.2253 2010-01-01 23.0152 2011-01-01 21.3045 2012-01-01 19.6461 2013-01-01 17.3493 2014-01-01 14.7387 2015-01-01 13.9914 2016-01-01 12.4552