Year	Number
2004-01-01	33
2005-01-01	37
2006-01-01	43
2007-01-01	48
2008-01-01	50
2009-01-01	52
2010-01-01	55
2011-01-01	58
2012-01-01	59
2013-01-01	70
2014-01-01	73
2015-01-01	72
2016-01-01	75
2017-01-01	75