Field help (RUBITV) 

Specify the ranges and expressions of the heading amounts by interval depending on the base:

If

base < 1st range

amount = 0

If  

base >= 1st range

amount = 1st amount

If 

base >= 2nd range

amount = 2nd amount... etc.

If

base >= last range

amount = last amount

SEEINFO There can be 10 intervals maximum.