Year Number 2008-01-01 11.1948 2009-01-01 13.9991 2010-01-01 16.4857 2011-01-01 19.9615 2012-01-01 20.7412 2013-01-01 43.7636 2014-01-01 45.1360 2015-01-01 45.2776 2016-01-01 49.7947