Year	Number
2004-01-01	40.9916
2005-01-01	40.1163
2006-01-01	39.6774
2007-01-01	40.2447
2008-01-01	39.4071
2009-01-01	39.6081
2010-01-01	38.7903
2011-01-01	38.3436
2012-01-01	38.4902
2013-01-01	34.4496
2014-01-01	31.8473
2015-01-01	31.1933
2016-01-01	30.6455
2017-01-01	29.4515