I don't think I can give concrete values, but I'd imagine Arona would be the most corrupt by far (most of the Kervus tribe, including her, pursue their goal(s) regardless of the consequences, which is a classic sign of Corruption/demonhood), followed by Quin (he was a cultist, after all). Azzy might have some residual Corruption due to what happened to her hive, but not enough to consider her tainted unless she equips her bimbofying necklace; either way, it means she's the only companion with physical Corruption as opposed to mental Corruption. The rest are all firmly in the very low range, though the stick up Kiyoko's ass makes me think she might be on the higher end of that range.
Of course, if any companions become demons (I've heard this might become a possibility for Arona, Brienne and/or Ryn), that's automatically 100 Corruption regardless of any other factors (and negates the point about Azzy being the only physically Corrupted companion).
