Year	Number
2007-01-01	756
2008-01-01	6266
2009-01-01	8331
2010-01-01	10667
2011-01-01	12154
2012-01-01	15297
2013-01-01	6830
2014-01-01	8397
2015-01-01	0
2016-01-01	0