Year	Number
2004-01-01	672
2005-01-01	1180
2006-01-01	1641
2007-01-01	3365
2008-01-01	3931
2009-01-01	8188
2010-01-01	7837
2011-01-01	8818
2012-01-01	8341
2013-01-01	6027
2014-01-01	8044
2015-01-01	13656
2016-01-01	16951