Year	Number
2004-01-01	6046569
2005-01-01	5905627
2006-01-01	6674839
2007-01-01	7608450
2008-01-01	8422632
2009-01-01	14048437
2010-01-01	14707820
2011-01-01	15724272
2012-01-01	16876798
2013-01-01	18079359
2014-01-01	18303510
2015-01-01	20053449
2016-01-01	21491075
2017-01-01	21969317