The pie charts indicate changes in the proportions of energy produced in a country from 1983 to 2003 Summarize the information by selecting and reporting the main features and make comparisons where relevant

The given pie charts compare the energy production percentage of one country in a period from 1983 to 2003.
It is obvious that this country almost had no development in hydropower, while oil always occupied the biggest proportion, though there was a decrease in the examined years.
In 1983, oil took up over two-fifths of the production. Coal and nuclear power are relatively close with the figures being 23% and 20% respectively. The remaining productions belong to natural gas with 11% and the smallest 4% hydropower.
In 2003, almost all kinds of energy had changed in their production except hydropower. In decreasing, oil still accounted for the biggest percentage of 38%, with a small minority of coal production. On the other hand, nuclear power and natural gas slightly increased by 24% and 21% respectively.