For the years 1980 to 1981 the data source is
EIA.
For the years 1982 to 1989 the data source is
World Bank.
For the years 2000 to 2006 the data source is
Ember.
For the years 2011 to 2012 the data source is
IEA.
For the years 2014 to 2018 the data source is
IEA.
For the years 2019 to 2023 the data source is
Ember.