I disagree. I think that
you should be getting at least a pass mark from taking the mocks for the first time. And then reviewing the questions in depth afterwards. I dont really see any point in measuring you ability to do the exam from additional taking of the same mocks over and over until you get 85% + . This only serves for you to learn the questions and not the principals behind them. Try only to take each exam once and learn from your mistakes so that if/when you take the same exam again you get a good mark.