Year	Number
2004-01-01	158
2005-01-01	168
2006-01-01	173
2007-01-01	188
2008-01-01	195
2009-01-01	202
2010-01-01	197
2011-01-01	182
2012-01-01	178
2013-01-01	172
2014-01-01	174
2015-01-01	174
2016-01-01	168
2017-01-01	168