Year	Number
2004-01-01	13939710
2005-01-01	14426021
2006-01-01	15296567
2007-01-01	18304063
2008-01-01	21145647
2009-01-01	24076657
2010-01-01	26575053
2011-01-01	28445078
2012-01-01	34065306
2013-01-01	35291073
2014-01-01	35779561
2015-01-01	35376059
2016-01-01	37758582
2017-01-01	39153709