Year	Months
2004-01-01	6.66373914594910
2005-01-01	5.40206623298044
2006-01-01	5.52189305265651
2007-01-01	5.50366181452965
2008-01-01	5.05121252861033
2009-01-01	4.86805289709377
2010-01-01	3.88740744475477
2011-01-01	3.65787410482039
2012-01-01	4.71797655796839
2013-01-01	4.78945997424572
2014-01-01	5.26610613805447
2015-01-01	5.41540045940612
2016-01-01	5.09935256334185
2017-01-01	4.96728835592356
2018-01-01	4.39776846348975
2019-01-01	4.23049255878523