These two charts shows the changes in the sources of energy in United States between 1980 until late of 1990.
Firstly, in the first charts in 1980s, the oil was 42% comparing to 33% in the second chart in 1990. Nature gas has increased only 1% in 1990 and also coal increased around 5%. Hydroelectric power maintain a 5% in both charts. And nuclear power doubled in the 1990s.
Secondly, I can see clearly that all the sources has slightly increased and also decreased by years between 1% to maximum 11%.
However, the changes in the main sources of energy affected by the changes of the nature in the country. Therefore, the oil and also the nature gas are still the biggest sources of energy in the United States. While the hydroelectric power and nuclear power are the smallest sources of energy and the changes were almost constant in the whole period between the 1980s untill 1990s.