Year	Number
2004-01-01	1.7371
2005-01-01	1.7174
2006-01-01	1.6974
2007-01-01	1.6533
2008-01-01	1.6347
2009-01-01	1.5919
2010-01-01	1.5950
2011-01-01	1.5757
2012-01-01	1.7498
2013-01-01	1.7028
2014-01-01	1.6573
2015-01-01	1.6335