Year	Months
2004-01-01	1.81866866905197
2005-01-01	2.05206738960454
2006-01-01	2.24045011406531
2007-01-01	1.94244779746419
2008-01-01	2.30416612727356
2009-01-01	2.64940219247023
2010-01-01	1.91128189591932
2011-01-01	2.21407456055153
2012-01-01	2.44830875442351
2013-01-01	2.03055087194200
2014-01-01	2.34295499224605
2015-01-01	2.20428412435480
2016-01-01	1.97397953372909
2017-01-01	1.51130065736377
2018-01-01	1.46771004993484
2019-01-01	1.37964129185613