Year	Number
2004-01-01	21.3401
2005-01-01	20.2338
2006-01-01	18.8451
2007-01-01	18.2745
2008-01-01	18.3143
2009-01-01	18.1417
2010-01-01	17.9077
2011-01-01	12.9980
2012-01-01	12.8575
2013-01-01	12.0193
2014-01-01	13.7591
2015-01-01	10.9894
2016-01-01	11.7484