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

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

energy

sources which as oil, natural gas, coal, hydroelectric

power

and nuclear

power

. Looking from an

overall

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

energy

source

while

hydroelectric was the least

energy

source

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

energy

source

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

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

In addition

, 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

source

which has increased in 1990 with compared to 1980.

Although

, nuclear

power

witnessed a percentage of about 5% in 1980

but

Remove the conjunction

apply

show examples

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

Furthermore

, we can see that hydroelectric

power

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