Year Number 2007-01-01 11.2825 2008-01-01 11.9902 2009-01-01 12.0894 2010-01-01 12.3335 2011-01-01 13.1836 2012-01-01 13.3433 2013-01-01 13.4672 2014-01-01 13.5681 2015-01-01 14.2585 2016-01-01 14.3364 2017-01-01 13.6168