Year	Number
2004-01-01	18640927
2005-01-01	21951298
2006-01-01	23156106
2007-01-01	24779284
2008-01-01	29482716
2009-01-01	32641631
2010-01-01	34382012
2011-01-01	37933259
2012-01-01	39440522
2013-01-01	38974819
2014-01-01	40413990
2015-01-01	41149587
2016-01-01	41862245