Year	PPP $ per kg of oil equivalent
1995	2.6683651979066316
1996	2.4026037276643795
1997	2.4857413168153015
1998	2.604040447096381
1999	3.2773948125359555
2000	3.2961040781298965
2001	3.2509767701879615
2002	3.474294299090459
2003	3.4383612411589968
2004	3.50094125892072
2005	4.251581835876293
2006	4.4372994166932
2007	4.999043125065412
2008	5.516069127008446
2009	6.054096879425175
2010	5.97626343573863
2011	6.1436253640872565
2012	6.896249114994101
2013	7.029537318332653
2014	7.883353280865723