Year Number 2008-01-01 4.4309 2009-01-01 4.2955 2010-01-01 4.3357 2011-01-01 4.5000 2012-01-01 4.2878 2013-01-01 4.3644 2014-01-01 3.5362 2015-01-01 5.0944 2016-01-01 5.0956