Year	constant 2011 PPP $ per kg of oil equivalent
2000	7.31894590426425
2001	7.12199471026373
2002	10.4769942056425
2003	10.4393079920176
2004	10.3376060004155
2005	9.42840108366734
2006	10.495258984003
2007	11.6583805971544
2008	11.4955587006727
2009	11.7929188602171
2010	10.4236008021282
2011	11.3270943027231
2012	10.4246533334209
2013	12.0905418974559
2014	12.1530848321154