I really don't think this is an accurate survey at all. You have to just go up to people in the flesh and ask them on the spot. See how that goes. I knew the answer, but I studied it in college, so I felt like I should.
A really good spot poll like this I did recently was to ask people "What's the highest court in Australia?" This is a question that is apparently going to be on new citizenship tests for immigrants. Everybody I asked except for people who studied law said "The Supreme Court" - which is false, Australia has no federal supreme court - "The highest court in Australia" is, of course, the High Court. The highest court in the US is the Supreme Court. So it turns out, as predicted by the local paper, the majority of Australians do not know enough about our country to become citizens... Interesting.