The two graphs show the main sources of energy in the USA in the 1980s and the 1990s. Write a report for a university lecturer describing the changes which occurred.

The two pie charts depict the USA's main

energy

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sources in 1980 and 1900.In evident that there are five

energy

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sources which as oil, natural gas, coal, hydroelectric

power

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and nuclear

power

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. Looking from an

overall

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perspective, it is readily apparent that in both years oil was the most

energy

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source

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while

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hydroelectric was the least

energy

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source

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. Looking at the details, we can see that the main

energy

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source

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in the USA was oil which accounted for 42% in 1980 when compared to after 10 years it significantly decreased by about 33% respectively.

Moreover

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, natural gas in 1980 where about 26% but in 1990 it slightly decreased to 25%

In addition

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, as can be observed from the pie charts coal was 22% in 1980 when the next decade proportion accounted for 27% respectively.Even though,coal was the only

energy

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source

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which has increased in 1990 with compared to 1980.

Although

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, nuclear

power

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witnessed a percentage of about 5% in 1980

but

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apply

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in 1990 it increased to 5% which was 10% in 1990.

Furthermore

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, we can see that hydroelectric

power

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only remains no change in the proportion which is 5%.