A sizable percentage of the human population is deathly allergic to bananas.
I'm mildly allergic to bananas, but I don't think the number of people allergic to bananas is "sizable."
My son is not, and he will let you know how not allergic he is to Bananas if he sees any that he is not eating.
And this is relevant how?
I'm mildly allergic to bananas, but I don't think the number of people allergic to bananas is "sizable."