How to determine data transmission rate from an eye diagram?
Observations:


Symbol lenght appears to be 2µs, and there are three voltage levels.
There is no transition from 1V to 2V in the diagram.


Hypothesis: There is a coding on top that pairs two symbols to encode 3 bits, and the eye diagram was recorded relative to the start of symbol pairs.

In this case, you get 3 bits per 4µs.