I prefer a harder reading level so I have no first hand knowledge, but I’ve seen many times on Redd¡t and other discussion forums that around 40-50 is more functional, 60-70+ is more on the exciting side of reading. But I have a pretty shit memory, so it could be higher but I’m fairly confident that it wouldn’t be any lower. From what little I (might) remember the former was mentioned to be more in the range of your question, so my best guess is 25-40 would be ballpark where you’d like to be. It’s not really sensitive material to read from what I’ve gathered, so if you overshoot a little bit it won’t be dangerous and shouldn’t be uncomfortable.
As much as I don’t like to because it’s not known to be very credible, but often times it’s the only place to find the kind of info you’re after, I suggest searching the name on Redd¡t to find a more experienced answer. You might be able to find something on an HR site as well(tbh I only know one, but I mentioned the name before and it got removed) but iirc majority of the info on it was years old and related to an older, better edition of it, and the one available today isn’t quite as good. But again my memory is shit so I could be wrong.