IELTS TASK 1 + 2: The amount of electricity produced from different energy sources

Electricity supplied to the New York (1980-2000)

IELTS TASK 1: : The graph below shows the amount of electricity produced from different energy sources to supply the city of New York between 1980 and 2000.
The line graph illustrates the data of electricity which is generated from three kinds of fossil resources to supply New York from 1980 to 2000.
Overall, it is clear that the amount of electricity produced by natural gas and petroleum witnessed an upward trend while this figure for coal slightly fluctuated over the same research period.

In 1980, about 350 million kilowatt-hours are generated by petroleum, compared to only 100 million of coal. After fluctuating significantly in the next 10 years, this figure for petroleum surged considerably to more than 700 million, reaching the peak at the end of the period. Similarly, natural gas experienced a significant increase throughout the research period. It finished at approximately 500 million in 2000.

In terms of coal, there are more than 200 million kilowatt-hours produced by this kind of energy source in 1980. It slightly rose to 300 million in the next 5 years. After that, this figure gradually dropped over the remainder of the time surveyed. Therefore, only less than 200 million kilowatt-hours are generated by coal in the year 2000.

@lehoang1294
I believe there should be only one essay per post. Also for Task 1 you should upload the actual graph, there is a button for adding images.

Task 1
Check you tenses. You should not use the present simple as all the data comes from the past. is was generated from

kilowatt-hours are were generated

You are overusing over the period variations: the same research period; at the end of the period; throughout the research period; the remainder of the time surveyed