Year Number 2007-01-01 261.2285 2008-01-01 281.6331 2009-01-01 245.5297 2010-01-01 224.7921 2011-01-01 217.3111 2012-01-01 212.7300 2013-01-01 218.4282 2014-01-01 221.1064 2015-01-01 222.2231 2016-01-01 224.4065 2017-01-01 231.7715