Year	Number
2004-01-01	590
2005-01-01	534
2006-01-01	647
2007-01-01	630
2008-01-01	592
2009-01-01	1117
2010-01-01	964
2011-01-01	1214
2012-01-01	4200
2013-01-01	4528
2014-01-01	5476
2015-01-01	5669
2016-01-01	5727