The pie charts compare six different sources in terms of their contribution of total energy generation in a country between 1985 and 2003.
In 1985, natural gas was the dominant source of energy, making up 52% of the total energy production. This was followed by nuclear energy at 22%. Oil contributed 13% of the total, whereas coal and hydrogen accounted for 8% and 4%, respectively. Energy generated from other renewable sources was minimal, at only 1%.
By 2003, natural gas remained the leading energy source, though its share dropped to 33%. Oil rose to become the second most significant source, supplying 23% of the country’s energy. Coal followed closely with 22%. Meanwhile, nuclear energy saw a significant decrease, contributing only 8%. Hydrogen, which stayed constant at 4%, was the only source that did not change over time. Interestingly, the percentage of energy from other renewables dropped further, reaching negative 3%—indicating a complete phase-out or data inaccuracy.