GDP per unit of energy use (PPP $ per kg of oil equivalent) - TongaIEA Statistics © OECD/IEA 2014 ( iea.org/data-and-statistics ), subject to iea.org/termsLicense : Use and distribution of these data are subject to IEA terms and conditions. LineBarMapAlso ShowNoneAggregatesSame regionSimilar valuesHighest valuesLowest valuesShareDetailsLabel