Year	Number
2004-01-01	10
2005-01-01	15
2006-01-01	16
2007-01-01	17
2008-01-01	18
2009-01-01	18
2010-01-01	19
2011-01-01	23
2012-01-01	30
2013-01-01	31
2014-01-01	33
2015-01-01	45