Year Number 2004-01-01 2.906223782 2005-01-01 2.061793678 2006-01-01 2.323962481 2007-01-01 2.019125014 2008-01-01 5.083650947 2009-01-01 5.006793851 2010-01-01 8.194188608 2011-01-01 9.013559166 2012-01-01 8.922276518 2013-01-01 10.786661930 2014-01-01 11.335785850