Year Number 2004-01-01 18.6433 2005-01-01 19.7774 2006-01-01 27.9630 2007-01-01 32.5445 2008-01-01 36.4619 2009-01-01 43.7001 2010-01-01 50.4970 2011-01-01 55.8187 2012-01-01 63.8317 2013-01-01 67.5085 2014-01-01 81.0310 2015-01-01 80.0468 2016-01-01 79.1573