The pie charts compare the sources of electricity in one country in 1990 and 2020.
Overall, the country moved away from coal and towards renewable sources and gas. Coal was the dominant source in 1990, but by 2020 it had become the smallest of the four.
In 1990 almost half of the electricity, 48%, came from coal, followed by nuclear power with 27% and gas with 20%. Renewable sources supplied only 5%. Thirty years later the picture was very different. Coal had dropped to just 12%, a quarter of its earlier share, and nuclear power also declined, to 20%.
Gas and renewables increased their shares dramatically. Gas rose from 20% to 36% and became the single largest source in 2020. The growth of renewables was even more striking, as their contribution climbed from 5% to 32%, more than six times as much as before. By 2020 gas and renewables together provided 68% of the country's electricity, compared with only 25% in 1990.
In contrast, coal and nuclear together fell from 75% to 32%.