Year	Number
2004-01-01	21.1629
2005-01-01	20.1689
2006-01-01	19.6273
2007-01-01	20.0168
2008-01-01	20.6060
2009-01-01	21.0419
2010-01-01	20.3970
2011-01-01	19.5689
2012-01-01	18.8974
2013-01-01	19.2046
2014-01-01	17.5640
2015-01-01	16.8879
2016-01-01	16.3488