Year	Number
2004-01-01	233
2005-01-01	267
2006-01-01	299
2007-01-01	347
2008-01-01	381
2009-01-01	391
2010-01-01	409
2011-01-01	442
2012-01-01	473
2013-01-01	485
2014-01-01	509
2015-01-01	526
2016-01-01	523