Note that the MaxValue property value needn't necessarily be greater than the ArcScale.MinValue. For instance, if you switch their values, this will simply change a circular scale's direction.
MinValue = 0, MaxValue = 100 (Default)
MinValue = 100, MaxValue = 0 (Rotated)
While the MinValue and MaxValue properties define the limit values, the number of tickmarks (and therefore labels) between them is specified by the ArcScale.MinorTickCount and ArcScale.MajorTickCount properties. The following images demonstrate how these properties can be modified together to customize the circular scale.