Year	Number
2004-01-01	6270163
2005-01-01	4442783
2006-01-01	5120663
2007-01-01	6026605
2008-01-01	7312517
2009-01-01	7473998
2010-01-01	8651994
2011-01-01	9877948
2012-01-01	11423424
2013-01-01	13161349
2014-01-01	15263276
2015-01-01	16912370
2016-01-01	18945415
2017-01-01	20070386