Year	Months
2004-01-01	3.43584910598323
2005-01-01	3.28765345189018
2006-01-01	4.89796481385358
2007-01-01	4.14345463884232
2008-01-01	7.11726404742997
2009-01-01	6.63723866142428
2010-01-01	3.86749146368249
2011-01-01	4.58766112248447
2012-01-01	3.46998876376626
2013-01-01	3.33077539373298
2014-01-01	4.05409530684991
2015-01-01	4.65979985943036
2016-01-01	3.92605604405650
2017-01-01	3.26616243524727
2018-01-01	3.29516071574176
2019-01-01	3.32569463991176