[liability]

Some people you might expect to have a very high bps, like auctioneers, are actually using a sort of parlor trick to create the illusion of rapid speech (a form of intention skillful stuttering which, when done right, is perceived as very fast speech.)

I expect some people are capable of some small multiple of this average, but probably not anything seriously dramatic.

(Of course there seems to be no lower bound, as in the case of involuntary stuttering.)