Year	Number
2004-01-01	16494006
2005-01-01	16941370
2006-01-01	19648994
2007-01-01	21607735
2008-01-01	23908009
2009-01-01	25732675
2010-01-01	27446300
2011-01-01	29813932
2012-01-01	31418612
2013-01-01	33005586
2014-01-01	34439625
2015-01-01	35973565
2016-01-01	36093471