Year	Number
2004-01-01	1.7329
2005-01-01	1.8344
2006-01-01	1.9023
2007-01-01	1.9517
2008-01-01	1.9384
2009-01-01	1.9331
2010-01-01	1.8406
2011-01-01	1.7562
2012-01-01	1.6984
2013-01-01	1.6710
2014-01-01	1.6447
2015-01-01	1.5941