You may not be able to discover all the numbers you need. But the question asks you to try. So your answer should document how you tried. What google searches did you perform? What web sites did you reach? Which ones were useful, which not? On the basis of what you discovered, what's your best estimates for what we asked for? What's your confidence in the accuracy of that estimate?
Note. The sentence "I think the number is xx." is not a good answer if that's all you say. We're not asking your opinion. You must follow that answer with a paragraph that says "I think so because ..."