Calculate volume discounts on a sliding scale

[Legacy 329465]

I am trying to calcluate a volume discount based on a sliding scale. The maximum discount is 1/3 of 1% or 0.33% at
$2,000,000 and higher.

Lower Limit	Upper Limit	Available Volume Discount
	499,999	0%
500,000	1,999,999	Sliding Scale
2,000,000	none	100%

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