Year	Number
2004-01-01	18.1407
2005-01-01	18.2792
2006-01-01	18.6452
2007-01-01	18.9531
2008-01-01	19.5548
2009-01-01	21.0993
2010-01-01	21.3114
2011-01-01	21.6119
2012-01-01	21.9107
2013-01-01	22.2379
2014-01-01	22.4703
2015-01-01	21.7166
2016-01-01	20.3989