Perhaps it ranges (if a measurement).

But my best guess is they simply _cannot know_ because the usage patterns of the new elevators will be different from the old elevators based on dispatching and sequencing and call systems. In other words, even if they know the exact consumption of the old system, and even if they expect precisely the same number of passengers per day, the _actual operating cost_ will depend on who arrives in the lobby, at what time, destined for which floors, and all other traffic patterns throughout the year.