Year	Number
2004-01-01	0.5303
2005-01-01	1.0713
2006-01-01	1.0607
2007-01-01	1.1561
2008-01-01	1.3895
2009-01-01	2.1532
2010-01-01	2.5244
2011-01-01	3.3517
2012-01-01	3.9139
2013-01-01	4.3594
2014-01-01	4.7624
2015-01-01	5.0806