Hi,
No, there's no way to do that. That's not how it's set up.
Every time an item is spawned a category is chosen based on category probabilities,
then an item is chosen from the category, based on that categories item probabilities.
It's two stages.
"I have Ammunition set to 10 and Attire set to 1"
With it set like that, every time an item is spawned theres a ten in eleven chance it will be Ammo, and a one in eleven chance it'll be Attire,
assuming both of those categories have items in them with probability > 0.
It's not realistic to 'follow' the maths. I just set everything to 5 then turn things up and down until it seems good.
If that doesn't allow enough room then set everything to 10 and adjust around that..