Year	Number
2004-01-01	160
2005-01-01	153
2006-01-01	154
2007-01-01	154
2008-01-01	150
2009-01-01	147
2010-01-01	145
2011-01-01	142
2012-01-01	142
2013-01-01	147
2014-01-01	148
2015-01-01	143
2016-01-01	141
2017-01-01	139