The pie chart illustrates the main sources of energy for the U.S.A. in 1980 and 1990. Overall, it is clear that there was an increase in the proportion of energy from coal and nuclear power, while the opposite was true for oil. It is also worth mentioning that the figures for natural gas and hydroelectric power remained more or less unchanged. Moreover, oil witnessed the largest change in energy production over the given period.
In 1980, the percentage of energy from coal was 22%, while in 1990 it rose to 27%. The percentage of energy from nuclear power was 5% in 1980; however, in 1990 it dramatically increased to 10%. It is also notable that, from 1980 to 1990, the figure for energy from hydroelectric power was 5% and stable.
The percentage of energy from natural gas saw a decrease of varying degrees between 1980 and 1990, from 26% to 25%. It is also clear that, in 1980, the proportion of energy from oil was 42%, but in 1990 it negligibly decreased to 33%.