Year Number 2004-01-01 16.6765 2005-01-01 19.2831 2006-01-01 19.7366 2007-01-01 22.4381 2008-01-01 33.5963 2009-01-01 35.6893 2010-01-01 39.1671 2011-01-01 50.0027 2012-01-01 50.4992 2013-01-01 64.9160 2014-01-01 67.7666 2015-01-01 85.4450 2016-01-01 90.7804 2017-01-01 55.0431