My answer:
The given pie charts outline the key energy categories over a 10 year period in the United States, as percentages.
Overall, in both years oil accounted for over half of all energy sources, while the least was in sections hydroelectric and nuclear power. There was only a minimal increase in coal and nuclear power, whereas the minimal decrease occurred in oil and natural gas.
Energy produced by oil comprised of 42% in 1980 and by 1990, it decreased by about 9% to 33%. Likewise, the amount of energy generated by natural gas went down by 15% from 26% in the first year to 25% by the final year.
Coal, on the other hand, had 22% share of all energy in 1980 then 10 years later it rose by 5% from 22% to 27% in the final year. In the first year, hydroelectric and nuclear power was 5% respectively, but then nuclear power increased its share twice, whilst the hydroelectric power remained the same.