Year	Months
2004-01-01	1.461325354436480
2005-01-01	1.188025938849000
2006-01-01	1.400600460736990
2007-01-01	2.445273485413450
2008-01-01	3.297016741295500
2009-01-01	3.862529410091730
2010-01-01	2.959719534216520
2011-01-01	2.947213382997960
2012-01-01	2.781549357577540
2013-01-01	2.117835829341220
2014-01-01	1.821881677802330
2015-01-01	2.892472279106960
2016-01-01	2.636901464627050
2017-01-01	1.579222787616150
2018-01-01	1.471973998072060
2019-01-01	0.980418332482605