Year	Number
2004-01-01	6668539
2005-01-01	6410415
2006-01-01	7271002
2007-01-01	8357213
2008-01-01	9165506
2009-01-01	14933619
2010-01-01	15687981
2011-01-01	16968986
2012-01-01	18257850
2013-01-01	19492232
2014-01-01	21318224
2015-01-01	23035470
2016-01-01	24153449
2017-01-01	25882055