Year	Number
2004-01-01	192
2005-01-01	192
2006-01-01	188
2007-01-01	184
2008-01-01	183
2009-01-01	178
2010-01-01	181
2011-01-01	180
2012-01-01	181
2013-01-01	186
2014-01-01	185
2015-01-01	184
2016-01-01	184
2017-01-01	188