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 pie charts illustrate the major sources of energy in the USA between

1980s

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the 1980s

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and 1990s.

Overall

, what stands out from the graphs is that oil accounted for the highest proportion not only in

1980s

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the 1980s

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but

also

in

1990s

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the 1990s

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. Another striking factor is that all types of energy changed the figure with the exception of hydroelectric power. In terms of hydroelectric, it occupied only a tiny minority either in

1980s

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the 1980s

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or a decade after at 5%.

In contrast

, oil constituted the majority figure both in

1980s

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the 1980s

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and 1990 (42% for the former and 33% for the latter).

Moreover

, nuclear power was used

a

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apply

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twice higher in the 1990s as in the 1980s (10% against 5%). One prominent feature is that the data

of

Change preposition

on

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natural gas in

1990s

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the 1990s

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at 25%, was 1% lower than

the

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in the

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1980s. One difference between

1980s

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the 1980s

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and 1990s is that

while

coal made up nearly a quarter in

1980s

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the 1980s

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, it was over a quarter in

1990s

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the 1990s

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, 22% and 27% respectively.