Year	Number
2004-01-01	7.4268
2005-01-01	6.9478
2006-01-01	7.4108
2007-01-01	7.1339
2008-01-01	7.3836
2009-01-01	7.3070
2010-01-01	6.6211
2011-01-01	6.2390
2012-01-01	5.7372
2013-01-01	4.9383
2014-01-01	4.5222
2015-01-01	4.7217
2016-01-01	4.6126