Year Number 2004-01-01 61.37191854 2005-01-01 51.59810595 2006-01-01 41.31542835 2007-01-01 42.37185320 2008-01-01 46.01232394 2009-01-01 47.79361329 2010-01-01 59.78967356 2011-01-01 59.00253593 2012-01-01 71.56120554 2013-01-01 20.86244278 2014-01-01 48.30379747