The two graphs depict five fuel sources used for energy production in the USA in 1980 and 1990.
Overall, it is obvious that in both years, oil was the fuel source that was used the most to produce energy, and we can see a slight change in the rate of the other fuel sources used in 1980 and 1990.
In 1980, oil accounted for 42% of total energy production, but then during the 10-year period, the figure saw a dramatically decrease at 33%. In addition, natural gas proportion remained stable at 26% in 1980 and 25% in 1990 while the figures for coal recorded a significant increase in both years (22% compared to 27%).
Moreover, while the rate of hydroelectric power used to manufacture energy stayed unchanged over the period, standing at 5%, the proportion of nuclear power used went up twice, from 5% in 1980 and reached 10% in 1990.