The trouble with comparing the best to the worst is that there's really no floor for how bad a programmer can be. If an average programmer takes ten minutes to do a task, and a great one takes four, how long does an incompetent one take? Twenty minutes, thirty, an hour or two, never...?
Incompetent programmer will finish task in the same time as 10x but at the same time it will break production for 5h, losing 100h for company and another 5h for someone to fix it.
