One of the more novel findings is that avowed atheists fared best (20.9) , closely followed by Jews (20.5) and Mormons (20.3), with the various Christian denominations trailing behind.
Sadly there were insufficient Muslim, Hindu and Buddhist respondents to feature in the statistics.
Entertainingly, Pew have released a truncated quiz, which I recommend you give a go. Perhaps you could then post your percentage score, and religious affliation (if any). I may then update this article with a completely unscientific aggregation of the results.
My expectation (and hope) is that us Britons will fare a little better than our American cousins. As the man said, "Ye shall know the truth, and the truth shall make you free" (John 8:32).