Year	Number
2006-01-01	15327511
2007-01-01	17668092
2008-01-01	19656921
2009-01-01	21911173
2010-01-01	24870663
2011-01-01	28242166
2012-01-01	31695744
2013-01-01	35580582
2014-01-01	39769070
2015-01-01	44390343
2016-01-01	49394702