Overall, there was a slight decline in the proportion of sources of energy as oil and natural gas while an opposite trend can be seen in the percentage of coal and nuclear power. In addition, the majority of utilizing nonrenewable energy was oil in both 1980 and 1990.
The proportion of oil use started at 42% in 1980, after which it experienced an insignificant decline to approximately one in three in 1990. The figure for consuming natural gas began at around a quarter in 1980, and dropped minimally to 25% at the last period.
Conversely, about one fifth of coal, with a moderate growth to 27% in 1990. Notably, the quantity of hydroelectric power and nuclear power were equal at 5% at the beginning period, but the figure for hydroelectric power remained unchanged in 1990. Additionally, the proportion of nuclear power rose by twice in 1990.