Year	Number
2004-01-01	18.2201
2005-01-01	17.7742
2006-01-01	16.9726
2007-01-01	17.0158
2008-01-01	16.7678
2009-01-01	16.4367
2010-01-01	16.7748
2011-01-01	16.6531
2012-01-01	16.3007
2013-01-01	15.8533
2014-01-01	15.5137
2015-01-01	15.2574
2016-01-01	15.0845