Year	Number
2004-01-01	0.7414
2005-01-01	1.4538
2006-01-01	1.3953
2007-01-01	1.4741
2008-01-01	1.7163
2009-01-01	2.5741
2010-01-01	2.9175
2011-01-01	3.7470
2012-01-01	4.2235
2013-01-01	4.5362
2014-01-01	4.7805
2015-01-01	4.9247