Year Number 2004-01-01 7.8940 2005-01-01 19.9132 2006-01-01 31.8403 2007-01-01 51.7437 2008-01-01 58.1755 2009-01-01 40.1414 2010-01-01 35.2519 2011-01-01 34.8599 2012-01-01 38.6560 2013-01-01 41.5964 2014-01-01 45.7146 2015-01-01 45.3716 2016-01-01 37.5837 2017-01-01 60.9008