Year	Number
2004-01-01	22.8859
2005-01-01	22.3387
2006-01-01	21.4470
2007-01-01	20.9176
2008-01-01	20.4531
2009-01-01	20.0587
2010-01-01	19.5935
2011-01-01	19.0895
2012-01-01	18.7509
2013-01-01	18.3258
2014-01-01	17.8222
2015-01-01	17.3377
2016-01-01	17.0981