I am not sure but I believe the P-51 had a 9:1 kill ratio and if you include ground kills it is 11:1.
I believe the Bf 109 had a 12:1 against Russian aircraft.
It's not the kill ratio but the clame ratio. Even if we are speaking obout confirmed claims, it's change nothing. The facts that the plane is confirmed by the own pilot's side, does not mean there was a real shot from the archives of the other side.
Considering that the particular overclaim can easily reach from 1.2-1.5 to 1-15, 1-20 in some paricular cases, conversation about claims (confirmed or not) to losses isn't of any kind of historical interest without the confirmation from the archives of the other side.
Regards