Year	Number
2004-01-01	546
2005-01-01	474
2006-01-01	472
2007-01-01	637
2008-01-01	795
2009-01-01	781
2010-01-01	1276
2011-01-01	1496
2012-01-01	2122
2013-01-01	4365
2014-01-01	2435
2015-01-01	3855
2016-01-01	4620