Year	Number
2004-01-01	1.4872
2005-01-01	1.6234
2006-01-01	1.7372
2007-01-01	1.9277
2008-01-01	2.1509
2009-01-01	2.4886
2010-01-01	2.8100
2011-01-01	2.9734
2012-01-01	3.0278
2013-01-01	3.0442