Year	Number
2004-01-01	0.3636
2005-01-01	0.4346
2006-01-01	0.6651
2007-01-01	0.8514
2008-01-01	1.0553
2009-01-01	1.2593
2010-01-01	1.4012
2011-01-01	1.5520
2012-01-01	1.5963
2013-01-01	1.6850
2014-01-01	1.7914
2015-01-01	1.9510
2016-01-01	1.9954