Year Number 2004-01-01 0.0183 2005-01-01 0.0541 2006-01-01 0.1279 2007-01-01 0.2856 2008-01-01 0.5084 2009-01-01 0.6685 2010-01-01 1.0978 2011-01-01 1.4637 2012-01-01 3.4794 2013-01-01 3.2631 2014-01-01 4.7606