Track Junkies: What is your rear wheel bearing life ??

[BGTV8]

My car is sounding suspiciously like it is suffering bearing noise from the rear -could be rear wheel bearings, could be diff, and could even be gearbox as 6th is developing a case of the crunchies.

Before sticking it on the hoist and running it hot and wandering around the car with the engineer's stethoscope (screwdriver with plastic end to ear and steel end to hub/diff/gearbox housing), does any track junkie on the forum have any data on rear wheel bearing life ....

My car has covered 110,000 klics and done nearly 50 track days, so it has had a pretty severe spanking thus far (I already have good "life data" on front wheel bearings) and is still on original rear wheel bearings.

RB