You appear to have convinced yourself that the increase in words in the regulations has been brought about by the increase in passenger numbers. I would suggest that a far greater factor has been the increasing complexity of the aircraft and aircraft operations.
Over the years a good many additions to the regulations have been brought about either by accidents or by the introduction of new technologies. Concorde didn't bring an increase in passenger numbers, but I suspect that it brought about some additional regulations. Fly-by-wire didn't increase passenger numbers, but it probably brought about some new regulations. Spaceship II will undoubtedly result in some additional regulations, but it won't carry very many passengers.