Academic Index as it pertains to swimming

What exactly goes into the academic index as it pertains to swimming? Traditionally, it was act or sat and two subject tests and GPA. I’ve heard from a few families that the subject tests are not necessary. I’ve also heard it’s gpa, independent of course rigor. Please clarify.

Bumping.
I don’t think there is a specific AI for each sport though.

The academic index in the Ivy league is one third unweighted gpa or class rank if available, one third SAT/ACT, and one third SAT2s. If the school does not require the SAT2s, then it is one third unweighted gpa/class rank and two thirds SAT/ACT. Course rigor does not play into the calculation of the academic index.

You need to remember though that the AI is just a tool to quickly determine whether someone is recruitable. Course rigor is going to have a lot to do with whether a kid is ultimately admissable.