Year	Number
2004-01-01	6.4224
2005-01-01	6.5312
2006-01-01	6.5312
2007-01-01	6.3861
2008-01-01	6.4224
2009-01-01	6.5312
2010-01-01	5.6967
2011-01-01	6.1684
2012-01-01	6.5312
2013-01-01	6.6401
2014-01-01	6.7489
2015-01-01	6.8578