Year	PPP $ per kg of oil equivalent
1990	1.1421821736038955
1991	1.298157839145647
1992	1.6528853926195246
1993	1.699044172013287
1994	1.1320776108006994
1995	1.0422821432027547
1996	1.2962894749340441
1997	1.166820290811986
1998	1.2082826892238494
1999	1.2057049227197667
2000	1.29619973397033
2001	1.3572215176021385
2002	1.324398292258202
2003	1.2509153631687493
2004	1.2918818134600314
2005	1.4463197032152797
2006	1.6154821626989075
2007	1.6171832313250625
2008	1.8685507090601243
2009	2.271615071928195
2010	2.2006163031831063
2011	2.368008077062703
2012	2.510031970175605
2013	2.6569855086449228
2014	2.8336957853934597