The pie charts illustrate the proportion of the total energy produced using different resources in the United States of America for two separate year, 1980 and 1990.
Overall, oil is the most used resource for the production of energy in both the years, followed by coal and natural gas. The share of coal and nuclear power has shown increase in usage. Whereas, the usage of oil and natural gas declined.
In the year 1980, oil was the largest contributor to energy generation with almost half (about 42%) of the total energy produced from it. Furthermore, coal and natural gas also had a decent share in the total production of energy around 22% and 26%, respectively. The nuclear resources and hydroelectric resources were the least used with approximately 5% of the total energy produced by each.
After a decade later, in 1990, the usage of oil has shown significant reduction, resulting only 33% of the total energy produced from it. In contrast, the share of nuclear power and coal increased to about 10% and 27%, respectively. The portion of hydroelectric power remained the same at 5%, and natural gas decreased only one percent to 25%.