Year	Number
2004-01-01	6008423
2005-01-01	7263098
2006-01-01	8942319
2007-01-01	9974876
2008-01-01	11808739
2009-01-01	13385853
2010-01-01	13609738
2011-01-01	14326553
2012-01-01	14609642
2013-01-01	16108933
2014-01-01	18374403
2015-01-01	21666645
2016-01-01	23855775