Overall, oil remained the dominant source of energy in both decades, although its share declined over time. In contrast, the use of coal and nuclear energy increased, while hydroelectric power became less significant.
In the 1980s, oil accounted for the largest proportion of energy consumption, at just over two-fifths of the total. Natural gas was the second most used source, making up around a quarter, followed closely by coal at slightly over one-fifth. Nuclear and hydroelectric power contributed much smaller shares, at about 4% and 5% respectively, while other sources were negligible.
By the 1990s, the proportion of oil had fallen to roughly one-third. Coal usage rose noticeably to around 27%, overtaking natural gas, which remained relatively stable at about 25%. Nuclear energy also increased modestly, whereas hydroelectric power declined. Other energy sources showed a small but visible rise.