Year	Number
2004-01-01	0.1726
2005-01-01	0.1726
2006-01-01	0.2157
2007-01-01	0.2157
2008-01-01	0.2588
2009-01-01	0.5177
2010-01-01	0.6903
2011-01-01	0.7765
2012-01-01	1.0354
2013-01-01	1.3374
2014-01-01	1.8550
2015-01-01	2.2865
2016-01-01	2.6747