Year	constant 2021 PPP $ per kg of oil equivalent
2000	2.1713921212844194
2001	2.0690240790392695
2002	2.115929442894002
2003	2.2251128161757046
2004	2.1084361341259528
2005	2.205849086708283
2006	2.274665909379905
2007	2.054051850374292
2008	2.1939212158149206
2009	2.1289288660585086
2010	2.395209011713258
2011	2.0256295861798965
2012	2.40070036302267
2013	2.693976168800622
2014	2.4482158922115898