Year	PPP $ per kg of oil equivalent
1990	1.4384090627761223
1991	1.5427916935956099
1992	1.5802443989053039
1993	1.6790255148816746
1994	1.765773860097546
1995	1.9164171954812628
1996	1.767873922924295
1997	2.051256813701702
1998	1.9316047215581813
1999	1.812365096373845
2000	1.8715856811690295
2001	1.785093058156774
2002	1.7982151372834265
2003	1.8764181268568934
2004	1.9815257029206208
2005	1.8904726993482552
2006	1.977271052781339
2007	2.000162292346959
2008	2.1709969173385417
2009	2.0660042551999704
2010	2.0211292121703544
2011	2.0904221527976845
2012	2.2269785454950544
2013	2.1826432712892525
2014	2.218588322359722