The two pie charts illustrate how electricity was generated from six energy sources in a particular country in 1985 and 2003.
Overall, while natural gas remained the leading energy source, its share declined over time. Meanwhile, coal and oil became more prominent, nuclear energy declined considerably, and renewable sources gained modest but noticeable ground.
In 1985, natural gas accounted for the majority of electricity production at 52%, followed by nuclear power at 22%. Oil provided 13%, while coal made up just 8%. The remaining electricity came from hydrogen and other renewables, at 4% and 1%, respectively.
By 2003, the proportion of natural gas had fallen to 39%, though it was still the largest contributor. Both oil and coal rose significantly, reaching 23% and 22%, respectively. In contrast, nuclear power dropped sharply to 8%. Hydrogen remained unchanged, while renewables quadrupled, growing from 1% to 4%, indicating a shift toward cleaner alternatives.