Number correct on the first try

I am writing some self-check questions and I am giving the user unlimited tries (all MC questions), and they aren't scored.

Because the user eventually selects the correct response, the quiz results page always says they got all the questions correct, which of course is not true.

I cannot find a system variable that shows the number correct on the first try, though there certainly should be one.

Is there one?

I know I can create this through variables and advanced actions, but that's more trouble that it's worth.

Thanks.