Year Number 2004-01-01 4.8415 2005-01-01 4.8485 2006-01-01 16.2819 2007-01-01 18.1928 2008-01-01 20.3011 2009-01-01 17.6727 2010-01-01 6.0999 2011-01-01 5.7684 2012-01-01 5.5225 2013-01-01 5.7943 2014-01-01 6.0696 2015-01-01 5.9976 2016-01-01 5.2695