Good question!
JSLAW is very close. The mid level angler puts on about 55 to 105 hours annually now. The lower use, local and small reservoir angler will go from 75 down to 40, with casual anglers using even less. The upper levels of a touring pro will use from 275 down to 125 we find. we haved seen over 2000 hours in engines, though we get edgy over 1500 hours ourselves. We have seen engines with over 2400 hours and no major ordeals, and over 800 something usually has gone awry. Boat speeds seem to average around 45-50.
Tournament level BCB product has had hour meter capability in most engines since 1993 model year. We should have a better grasp on this than anyone. We just saw (2012) a late 1996 model year MH area angler rig, one owner with 362 hours on the engine. We know this angler well, he fishes a lot and once did that hard, just less running since 2000.
Fifteen years ago, before CY 2000 these numbers were:
Causal – 55 up
Local – 85 up
Regional – 125 up
National – 165 up
Today:
Casual – 20 up
Local – 40 up
Regional -55 up
National – 125 up
Obviously the price of fuel impacted this even with more efficient engines.