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The line graph shows the average monthly change in the prices of copper, nickel and zinc in 2014, compared with the previous month.
Overall, nickel had the biggest changes during the year, while copper was the most stable metal. All three metals had negative changes in the middle of the year, but they increased again at the end of the year.
In January, the price of nickel rose by 6%, which was the highest change of the year. However, it dropped quickly to 1% in March and fell to -3% in June. After that, nickel stayed at -1% from July to September and decreased to -2% in October, before it went up to 1% in the last two months.
Zinc started at 1% and reached 3% in February. Then it decreased slowly to -1% in June and stayed below zero until October. In contrast, copper changed only a little. It was around 0.5% to 2% for most of the year and only had a small negative change of -0.5% in May and June. At the end of the year, copper and zinc was at 1.5% and 2%.