An amazing distribution of scores

Today, I found a blog conducted by an Iranian sociology teacher, accidentally. I don’t know him at all. He has put the scores of his students on his blog, so I was motivated to find out how is the range of scores. I was shocked seeing the list! Most of them were lesser than 10 and there were several scores such as 2, 2.5, 3 and so on. It should be noted that in Iran, the range of scores in from 0 to 20. I recommend you to take a look at this teacher’s score list, here.
The title of that course, was “Introduction to sociology”! Are his students extremely weak? Or is he an autocratic teacher? I don’t know. Perhaps none of them, he is may be incapable of teaching sociology, as we can see most of his students has failed the exam.
By contrast, there are teachers in Iran, whose all students pass the exams with scores of more than 16 or 17. The distribution is interesting. I don’t believe that all scores must have the normal distribution, but something that has always been in my mind is the teachers’ self-confidence. Are their means of examination so accurate that leads them to giving such amazing scores?