If you think 4 Bongos are a lot, have a look up on Horn Island- 11 of the buggers in one spot!
Barrier have 6, West Wing have 3, Cape Air have 1 and the QLD Police have 1 (do they have their brand newie yet or still the lease from Tamworth?).
Google Earth has a good photo with a few sitting there, but not sure how long ago that was.
There is a decent concentration of them down in Tassie I think with Airlines of Tas, a couple of ex Regional Pacific machines (previously from Horn Island, too) went there.
Anyone know the numbers down there?