Year	Number
2004-01-01	0.0582
2005-01-01	0.0595
2006-01-01	0.0609
2007-01-01	0.0666
2008-01-01	0.0679
2009-01-01	0.0719
2010-01-01	0.0922
2011-01-01	0.0966
2012-01-01	0.1129
2013-01-01	0.1094
2014-01-01	0.1385
2015-01-01	0.1857