The graph below shows the average monthly change in the prices of three metals during 2014.

This

bar graph illustrates, for the three different types of metal, the average monthly

price

fluctuations in 2014.

Overall

, the

price

of copper and nickel decreased throughout the whole time frame,

while

that of zinc increased.   Focusing on the

price

of copper and nickel, they started with 2% and 6% changes in

price

in comparison with the previous

month

, respectively. The percentage of nickel experienced a significant drop by June, recording the lowest percentage at -3%. After that point, its

price

fluctuated and recovered

at

Change preposition

by

show examples

1%

at the end

of the

month

.

On the other hand

, the

price

of copper decreased slightly by May to -0.5% and rose gradually over the next seven months, reaching under 2%.   Turning to the

price

of zinc, its percentage was at 1% in the first

month

.

Although

it showed a surge of 3% the next

month

, it experienced a downward trend until June, recording a -1%. Over the next six months, though its

price

fluctuation was steady until October, it depicted a significant upward trend of 2% by December.