The pie charts below show the proportion of energy produced by different sources in one country in 1985 and 2003

The two pie charts compare the energy production of a nation in different years, 1985 and 2003, in terms of five distinctive sources.
Overall, Oil was the main sources of energy in both years, while the proportion of energy produced by Hydroelectric power remained unchanged between two years.
In 1985, 52% oil and 22% nuclear represented nearly third quarters of the total energy sources, while in 2003, the proportions reduced to 39% and 17% respectively. However, Oil remained the highest percentage of sources used for energy production.
In contrast, the proportion of energy originated from natural gas increased from 13% in 1985 to 23% in 2003, made up the second major source in this year. Similarly, coal was increasingly used for energy production over two years, rose by 5% in 2003. Whereas, hydroelectric power was the stable source in both years, accounted for just 4%, remained the smallest proportion of energy source in total.