Year	Number
2004-01-01	0.3523
2005-01-01	0.3883
2006-01-01	0.4186
2007-01-01	0.4470
2008-01-01	0.4621
2009-01-01	0.4792
2010-01-01	0.4735
2011-01-01	0.4678
2012-01-01	0.4678
2013-01-01	0.4754
2014-01-01	0.4830
2015-01-01	0.4830