When AIs start ranking humans

Right now humans are trying to determine, based on their output, which AIs are the most intelligent. How long will it be before AIs are in the position to determine, based on our output, which living and historical humans are the most intelligent? Equally interesting will be how they explain their ranking system and how authoritative its results will be held to be by academia and the rest of the world. Here I'm referring to what IQ tests attempt to measure but it would also be interesting to learn how they will rank humans in the other kinds of intelligences like social, musical and athletic.