Year	Number
2004-01-01	21.3015
2005-01-01	20.2097
2006-01-01	16.6951
2007-01-01	16.3157
2008-01-01	16.3244
2009-01-01	15.8650
2010-01-01	15.7119
2011-01-01	15.8465
2012-01-01	14.1807
2013-01-01	14.8931
2014-01-01	14.5507
2015-01-01	14.0467
2016-01-01	13.4592
2017-01-01	12.8983