Year	Number
2004-01-01	0.0464
2005-01-01	0.1015
2006-01-01	0.1341
2007-01-01	0.1857
2008-01-01	0.2356
2009-01-01	0.2648
2010-01-01	0.2872
2011-01-01	0.3317
2012-01-01	0.3764
2013-01-01	0.4091
2014-01-01	0.4813
2015-01-01	0.5552
2016-01-01	0.6411
2017-01-01	0.7253