This was emailed to me by a student earlier today. Thanks to years of training in the mystical arts of the statistik, I am able to pinpoint where exactly these values (the final marks of Polish high-schools students for the year) seem to come unstuck. You might find it more difficult, of course. Just bear in mind that 30% is the pass mark here.
(This does rather make me wonder if I can get away with something similar in this week's exam board, but I suspect this kind of of shenanigans is harder to pull off when surrounded by mathematicians.)