Consider them 100% PG if they are PG based.
Of course they are not, but they act the same as PG, so even if it isn't a duck, but quacks like a duck, swims like a duck, and acts like a duck, just call it a duck and move on. (We don't bother with the % of PG that isn't actually PG or the % of VG that isn't actually VG even though we know 100% is darn near impossible.)