Year Number 2007-01-01 173.3412 2008-01-01 171.2890 2009-01-01 171.5826 2010-01-01 186.1085 2011-01-01 189.1223 2012-01-01 421.6649 2013-01-01 490.7886 2014-01-01 505.9751 2015-01-01 545.8451 2016-01-01 564.3578 2017-01-01 560.3449