Year	Months
2007-01-01	3.471246600
2008-01-01	4.574609735
2009-01-01	5.142785610
2010-01-01	4.209601394
2011-01-01	4.181478085
2012-01-01	3.043623251
2013-01-01	2.780846686
2014-01-01	2.642321106
2015-01-01	2.672426926
2016-01-01	2.590418249