Year	Number
2004-01-01	0.334
2005-01-01	0.377
2006-01-01	0.399
2007-01-01	0.473
2008-01-01	0.542
2009-01-01	0.618
2010-01-01	0.663
2011-01-01	0.957
2012-01-01	1.532