What is the percentage of people who fail the learner's permit test the first time?

I looked around, I couldnt find a decent statistic, it was mostly Canadian articles. Does anyone know? Im trying to get an actual number after I heard a bunch of people whining about failing and their parents saying "They say 80% of people fail the first time". Im trying to confirm or deny that teenagers are really that stupid, in general. (I ped first time :-D)