There are a couple of ways to make yes and no plural:
…yeses and noes…
…yes’s and no’s…
I personally don’t like the look of noes because I think it looks like a misspelled word — maybe nose misspelled. So I would go with the forms that have the apostrophe.
No matter which of the forms you choose, you need to be consistent. Either make them both plural with the spelling, or make them plural with the apostrophe. Don’t mix them together.