A glance at the given pie chart reveals some striking similarities among the proportions of energy produced from six type of resources during the era from 1985 to 2003.
Overall, while the ratios of coal, natural gas and renewable energy were on an upward trend, the remains were sustainably unchanged or on the contrary trend.
In 1985, the figure for energy derived from natural gas was 13% which was 5% more than that of coal energy. Subsequently, in 2003, they gradually increased and nearly the same at 23% and 22%, respectively. 1% was the proportion of other renewable energy in 1985, before it neligibly enhanced to 4% in 2003.
In terms of downward trend, the percentage of oil energy in 1985 was the highest at 52%-more than a half, followed by nuclear energy at the second place with 22%. Similarly, they significantly declined to 39% and under 10% in 2003. By contrast, the figure for hydro energy was the same at 4% over the examined time.