Year	Months
2004-01-01	6.64510693402341
2005-01-01	4.74341837838080
2006-01-01	3.87750816616127
2007-01-01	4.24082747493147
2008-01-01	4.24492624312498
2009-01-01	4.64363618408162
2010-01-01	4.13000962784686
2011-01-01	3.48104967616347
2012-01-01	3.64593273960493
2013-01-01	3.95156501331584
2014-01-01	4.32190472469331
2015-01-01	4.65518166819473
2016-01-01	5.26000591456544
2017-01-01	5.32205055741684
2018-01-01	4.84779901594794
2019-01-01	4.65009224724774