Year	Number
2006-01-01	164
2007-01-01	168
2008-01-01	161
2009-01-01	161
2010-01-01	160
2011-01-01	160
2012-01-01	163
2013-01-01	167
2014-01-01	163
2015-01-01	165
2016-01-01	159
2017-01-01	151