Year	Number
2004-01-01	21566976
2005-01-01	21902081
2006-01-01	22381973
2007-01-01	22833628
2008-01-01	23550685
2009-01-01	23939556
2010-01-01	23985494
2011-01-01	23716487
2012-01-01	23886560
2013-01-01	23904268
2014-01-01	23662217
2015-01-01	23463982
2016-01-01	23535223
2017-01-01	22984754