Year Number 2004-01-01 0.0392 2005-01-01 0.2291 2006-01-01 0.2229 2007-01-01 0.2896 2008-01-01 0.3885 2009-01-01 0.8091 2010-01-01 1.4076 2011-01-01 2.7257 2012-01-01 4.6333 2013-01-01 5.1459 2014-01-01 5.5193 2015-01-01 5.5195 2016-01-01 5.6382 2017-01-01 5.7228