Year	Number
2004-01-01	0.2658
2005-01-01	0.3166
2006-01-01	0.4794
2007-01-01	0.5481
2008-01-01	0.6536
2009-01-01	0.7465
2010-01-01	0.9321
2011-01-01	1.0847
2012-01-01	1.2081
2013-01-01	1.3708
2014-01-01	1.6773
2015-01-01	2.0041
2016-01-01	2.1338
2017-01-01	1.8604
