Here is the guide. I have 97% confidence in the splits. [Keep in mind, the ratings are displayed as an integer figure, but the game preserves them as a fractional rating. It seems likely that the initial and potential category figure are integers....I've got about 75% confidence in that.]
MASSIVE 28+ High-High (significantly, tremendous, sky’s the limit, massive)
SUBSTANTIAL 21 – 27.99 Low-High (above average, substantial, really improve, major, big, lot, fairly significant)
GOOD 7 – 20.99 Average (good upside, decent, can improve, help improve, able to/should/could improve)
NOT MUCH 3.0 - 6.99 Low (not anticipating…much, don’t think/see…much more, probably not…much, etc.)
NOT ANY 0 - 2.9 Low-Low (don’t see any, doubt any, etc.