Year	PPP $ per kg of oil equivalent
2000	3.760641834526019
2001	3.897847950338674
2002	3.920317490362619
2003	4.057681309335874
2004	4.246719125282851
2005	4.4480094318949535
2006	4.668717094696036
2007	4.952294817167809
2008	5.137149134229567
2009	5.1580771701778
2010	5.320832451585253
2011	5.411501683999091
2012	5.259986889426514
2013	5.459943208241116