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

The line graph illustrates the average change of the costs through the months of

three

substances in 2014. In general,

nickel

tends to decline over time compared to

copper

and

zinc

, and these

three

metals bottomed out in June. Having looked at the given picture for details, in January,

nickel

and

copper

were at 6% and 2% before going down by 5% and nearly 0.5%, respectively in March. Meanwhile,

zinc

witnessed an increase from 1% to 3%

then

slightly dropping in the same month. In April, both

nickel

and

copper

remained steady

while

zinc

fell.

Three

percentages of

three

substances continued to fall and reached the lowest rate in June.

In contrast

, begin the end of June,

three

expenses of

copper

,

nickel

, and

zinc

went up and levelled off at 1%, -1%, and -0.5%, respectively. After that,

three

percentages slightly decreased before increasing and reached the final rate

at the end

of the year. Among that, the figure for

zinc

in December was more than in January by 1%.

By contrast

, the

nickel

's rate had a significant decrease to 1%, and

copper

's proportion witnessed a slight drop of approximately 0.2%.