Year Number 2004-01-01 168.1081 2005-01-01 165.9946 2006-01-01 163.7156 2007-01-01 159.6886 2008-01-01 158.4859 2009-01-01 156.2396 2010-01-01 151.2236 2011-01-01 151.4465 2012-01-01 151.2438 2013-01-01 155.9516 2014-01-01 170.2951 2015-01-01 176.9730 2016-01-01 183.4770 2017-01-01 189.6219