Year	Number
2004-01-01	2615794
2005-01-01	3246127
2006-01-01	3618428
2007-01-01	4507250
2008-01-01	5202086
2009-01-01	5831364
2010-01-01	6703111
2011-01-01	16993183
2012-01-01	16847740
2013-01-01	16881786
2014-01-01	17010465
2015-01-01	16051818
2016-01-01	16077594