Year	Number
2004-01-01	20.9697
2005-01-01	25.8016
2006-01-01	23.0972
2007-01-01	22.6873
2008-01-01	23.0179
2009-01-01	23.6903
2010-01-01	23.2820
2011-01-01	23.1391
2012-01-01	22.6654
2013-01-01	22.8597
2014-01-01	20.1616
2015-01-01	20.7076
2016-01-01	19.4307