Disfluencies -- trips of the tongue, "repairs" -- occur in normal preschool children around once every hundred words. In high school seniors, the least disfluent group, it goes down to four. As we age, the number goes up again (58).

yeah, this doesn't seem to follow. goes down to four every hundred, or goes down to once every four -- neither of these get you to "least disfluent" (or constitutes going "down").

-joe (disfused) friday