Year	PPP $ per kg of oil equivalent
1990	10.391849576041853
1991	10.535607605404579
1992	11.192975296225242
1993	11.275756656544482
1994	12.61985257728746
1995	11.734658858456173
1996	13.224827950255436
1997	13.970613269776582
1998	14.642876562138365
1999	14.69529929775054
2000	16.280852090745007
2001	15.415635993309323
2002	16.253739274587133
2003	14.159023046891312
2004	14.16850234054474
2005	14.553599387341018
2006	12.411487221647182
2007	13.403286467087558
2008	13.5721652976853
2009	13.351099846809046
2010	13.638203123076217
2011	10.68473348056299
2012	11.222723975709862
2013	10.794192764051093
2014	10.854797827009655