Year	Number
2007-01-01	1345270
2008-01-01	5082470
2009-01-01	8882580
2010-01-01	16446300
2011-01-01	19191000
2012-01-01	21060000
2013-01-01	25326333
2014-01-01	25249200
2015-01-01	31642400