How to have a percentage rating from a yes/no rating field?

I have a yes/no rate that is based on "Good for stomach" and people can click thumbs up/thumbs down or yes/no if its good for their stomach or not.

I see this is a points based rating but I want a percentage rating because I want to compare and sort lists of foods based on their percentage of yes to no's or thumbs ups to thumbs downs.

Hope that makes sense?

This is so I can show that a food has a 78% yes and 22% no and if people sorted a views list with the foods and all other foods had a smaller percentage of yes/thumbs up then they would be below so that they can see foods that are the best for most people for their stomach issues.

How would I go about this?