The pie charts illustrate the proportion of different sources (oil, hydroelectric, nuclear, coal, and natural gas) of energy for the USA in 1980 and 1990.
Overall, the main sources of energy production remained oil, natural gas, and coal, which accounted for more than 50% in both years. An increase was observed in the production of nuclear power and coal, whereas the remaining categories observed a decline, except hydroelectric power which remained unchanged.
Production of energy through oil, gas, and coal registered as 42%, 26%, and 22% respectively in the year 1980. On the other hand, hydroelectric power and nuclear power accounted for 5% each. Lastly, oil accounted for the main source of energy among the remaining.
Energy production from oil, and natural gas observed a decline and were accounted for a share of 33% and 25% respectively, in the year 1990. Nuclear power and coal both showed an increase in the production by 5%. However, hydroelectric power was the only source that did not show any change in the market share.