Year	Number
2004-01-01	16653951
2005-01-01	19963629
2006-01-01	23865958
2007-01-01	26196486
2008-01-01	29953681
2009-01-01	33281456
2010-01-01	38225736
2011-01-01	44195762
2012-01-01	47493646
2013-01-01	51597637
2014-01-01	54650431
2015-01-01	54519165
2016-01-01	55049207
2017-01-01	62619107