How do I know what the upper boundary is for a syllabus percentage uniform mark of 100? Say for instance 80/130 marks are needed for an A grade (80% percentile), and that 72/80 marks are needed for a B grade (70% percentile), what would be the minimum raw mark required for a 90% or a 100% percentile? Since the difference between A and B is 8 marks, would the middle of the A grade be 88/130 marks to get a 90% percentile?