Year	Number
2004-01-01	4.2497
2005-01-01	4.3295
2006-01-01	4.4206
2007-01-01	4.4472
2008-01-01	4.4776
2009-01-01	4.6257
2010-01-01	4.5308
2011-01-01	4.4890
2012-01-01	4.4396
2013-01-01	4.1472
2014-01-01	4.0447
2015-01-01	4.0447