My reccord is 150% in sec2 mathematics (statistics & probabilities module). There were 3 bonus questions which normally would've added up to a total of 110%. However, I took each of his bonus questions, and instead of answering them, I wrote a 3-page long explanation on why they were flawed and it was impossible to give a correct answer for them. The teacher was amazed and gave me 150% for the exam.
Second best score was 125% in sec4 mathematics (trigonometry module). Nothing special there, just got all the answers right plus all the bonuses.
I've also had a couple of 110%s and the like.
My lowest score ever was 10% in music. Go figure.
The music industry is a cruel and shallow money trench where thieves and pimps run free, and good men die like dogs. There's also a negative side.