Year Number 2004-01-01 19.4597 2005-01-01 27.6615 2006-01-01 32.4400 2007-01-01 32.5528 2008-01-01 32.4473 2009-01-01 25.3876 2010-01-01 20.7703 2011-01-01 17.2107 2012-01-01 16.0047 2013-01-01 13.9964 2014-01-01 13.8257 2015-01-01 13.2633 2016-01-01 14.4533