For the years represented on this chart, in which year was Canada’s relative contribution to world production highest? In which year was it lowest? What about the Democratic Republic of the Congo—...

For the years represented on this chart, in which year

was Canada’s relative contribution to world production highest? In which year was it lowest?

What about the Democratic Republic of the Congo—

what was its proportion of world production in 1990,

compared to the proportion in 2011, for example?