Year	Number
2004-01-01	0.1892
2005-01-01	0.1943
2006-01-01	0.2046
2007-01-01	0.2356
2008-01-01	0.2562
2009-01-01	0.2803
2010-01-01	0.3009
2011-01-01	0.3249
2012-01-01	0.3541
2013-01-01	0.3816
2014-01-01	0.4469
2015-01-01	0.5019
2016-01-01	0.5535
2017-01-01	0.6016