The two pie charts illustrate the main sources of energy in the USA in poth periods: 1980s and 1990s.
In general, it can be seen that depending on oil as a source of energy declined gradually; on the other hand, the dependance on natural gas did not change observably.
According to the data, it is obvious that the major source of energy in the USA was oil, as it occupied around , whereas coal as the third place with only . Both nuclear power and hydroelectric were %5 of energy sources, as there were small relience on them.
By contrast, in 1990s, several changes have occured; for instance, there was a drastic drop in the oil industry, as it became only . Natural gas, in contrast, did not witnessed a notable decline as it decreased with only %1. Moreover, the goverment managed to increase the relience on nuclear power as it doubled, whereas the hydroelectric power indusrty stayed the same.