Year	constant 2011 PPP $ per kg of oil equivalent
2000	5.82226718584156
2001	6.05665416160868
2002	6.00853534334389
2003	6.05849275951842
2004	5.79944712690798
2005	5.99602264390289
2006	6.185865992977
2007	6.09845011044435
2008	6.38290426732217
2009	5.97779937854172
2010	6.00122022771247
2011	7.06742233849245
2012	6.72190020865856
2013	5.61642691174729
2014	6.00035880939138