Year Number 2004-01-01 7.7328 2005-01-01 9.2248 2006-01-01 11.7683 2007-01-01 12.4834 2008-01-01 11.6976 2009-01-01 14.3203 2010-01-01 12.6124 2011-01-01 16.1422 2012-01-01 15.1381 2013-01-01 15.4537 2014-01-01 16.3774 2015-01-01 18.2839 2016-01-01 24.5712 2017-01-01 25.4457