Year	Number
2004-01-01	19169
2005-01-01	21776
2006-01-01	20353
2007-01-01	19007
2008-01-01	17609
2009-01-01	17114
2010-01-01	17261
2011-01-01	21214
2012-01-01	15313
2013-01-01	14077
2014-01-01	12933
2015-01-01	13226
2016-01-01	15273