Expeditions Dot System

General description of how the resources displayed with 0 to 4 dots works :

0 dot 1 dot 2 dots 3 dots 4 dots
resource range 0 1-240 240-480 500-650 750-2000

In those cases, the limits of the ranges are inclusive, so for instance, an expedition giving 240 resources can have either 1 or 2 dots, for no apparent reason.