Average Star ratings - at what point does it stop rounding down?

I have 6 reviews for location, which came up to an aggregate total of 28/30 stars. This is an average of 4.67/5.0. Same goes for value, which is 29/30 stars and works out to around 4.83/5.0.

How is it that my listing is still showing location and value as 4.5 stars? At what point does Airbnb stop rounding down?

IMHO half a star isn’t worth even thinking about. I hardly ever look at stars anyway. I’m not worried.