Year	Number
2004-01-01	16.2343
2005-01-01	18.1581
2006-01-01	18.7556
2007-01-01	20.8942
2008-01-01	20.6183
2009-01-01	20.2058
2010-01-01	20.2737
2011-01-01	23.1266
2012-01-01	23.0517
2013-01-01	22.5631
2014-01-01	22.3238
2015-01-01	22.3276
2016-01-01	21.7855
2017-01-01	21.0206