Score Perecentage per category in Results

Hello,

I would to design a quiz in which questiosn are drawn from 5 categories. In the results pagen, I would to have the score in terms of percentage (%) for every category. For instance, If the user answers all the questions in Category 1, he should get 100% in this category. if he answers only 5 out of 10 questions in category, he should get 50% in that cetagory, etc.

Thanks for helping