Year	Number
2004-01-01	13187
2005-01-01	15929
2006-01-01	16080
2007-01-01	18961
2008-01-01	21451
2009-01-01	21597
2010-01-01	17776
2011-01-01	24751
2012-01-01	21580
2013-01-01	24923
2014-01-01	21496
2015-01-01	21198
2016-01-01	22237