Year	Number
2006-01-01	19.2197
2007-01-01	19.5501
2008-01-01	19.4212
2009-01-01	18.8566
2010-01-01	18.7602
2011-01-01	19.9756
2012-01-01	20.7569
2013-01-01	19.3489
2014-01-01	21.0252
2015-01-01	16.1448
2016-01-01	16.5037