Year Number 2004-01-01 6.5164 2005-01-01 6.8249 2006-01-01 6.8692 2007-01-01 7.0512 2008-01-01 7.1506 2009-01-01 7.4955 2010-01-01 9.8508 2011-01-01 9.8575 2012-01-01 10.0070 2013-01-01 11.5613 2014-01-01 13.0076 2015-01-01 15.6410 2016-01-01 19.4435