Within an order of magnitude? You can't give a number within an order of magnitude? There's only 20 million Muslims in China. There's only 9 reasonable answers (10^0, 10^1, 10^2, ... ~10^8), and any answer you give covers 3. In fact, 10^0 and 10^8 aren't really "answers" because they're entirely dominated by the other options, so you have 7 reasonable answers.

You fucking kidding me? You might as well have said 0, because that's about as much good as your answer did. You made the claim, now back it up.