Year Number 2004-01-01 7.098509934 2005-01-01 7.595198675 2006-01-01 8.671357616 2007-01-01 8.878311258 2008-01-01 10.037251660 2009-01-01 10.368377480 2010-01-01 11.216887420 2011-01-01 12.872516560 2012-01-01 14.176324500 2013-01-01 14.176324500 2014-01-01 14.176324500