Year	Number
2004-01-01	17
2005-01-01	18
2006-01-01	21
2007-01-01	28
2008-01-01	31
2009-01-01	39
2010-01-01	59
2011-01-01	61
2012-01-01	72
2013-01-01	71
2014-01-01	69
2015-01-01	68
2016-01-01	57