Year	Months
2007-01-01	3.109652127
2008-01-01	2.790788841
2009-01-01	3.638088038
2010-01-01	4.589607725
2011-01-01	3.489016448
2012-01-01	2.526229244
2013-01-01	2.377712148
2014-01-01	3.031172289
2015-01-01	2.637529406
2016-01-01	2.848066889