You are given a passage. You need to construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) its answer is the whole paragraph. Avoid creating questions that can be answered correctly without actually understanding the paragraph.

I don't think it's possible to accurately answer that question.
Some countries may not even know themselves how many of their own people have gone missing, or even worse, mis-represent how many have gone missing due to the efforts of secret-police type organisations.

In some cases it's up to 3rd parties like the Red Cross to give numbers on thing like this, see:
http://www.redcross.org/news/in/africa/020130lagos.html
http://www.redcross.org/press/intl/in_pr/010412kosovobook.html
for example.
How many people go missing every year world wide?