The two pie charts illustrate, several main sources of energy in America in the 1980s and the 1990s. Overall, oil was the most dominant among all other categories in both years. Only one category remained constant called “hydroelectric power” while, some changes occurred in the others.
In 1980 oil was the most popular source of energy by (42%), However, it fell to (33%) in 1990 but, remained the highest proportion. Natural gas was the second highest percentage in 1980 by (26%) but, it dropped to a quarter in 1990. Even though coal was the third least popular source in 1980 but, it showed a dramatic increase from (22%) in 1980 to (27%) in 1990 replacing natural gas to become the second highest share.
Regarding the two remaining sources nuclear power and hydroelectric power were the least used sources in both years. These two categories had the same percentage in 1980 by (5%). In 1990 nuclear power increased significantly (5% percent more) to become (10%), meanwhile, hydroelectric power stayed constant.