DescriptionSets or returns the maximum value on the y axis.
When creating new charts, or reading in charts where this value is not set, this property will return 0, which represent that this property does not contain a value and Excel will automatically determine an appropriate maximum for your value axis. Unfortunately, there is no way to distinguish between this state and when the MaxValue property is actually set to zero.
This property can be set to less than the ValueAxis.MinValue, although that is an illegal state. We allow this so that the order of operations does not matter when setting both the MinValue and MaxValue to different values. However, if the MaxValue is still less than the MinValue when you try to save, the MinValue will be treated as the MaxValue and vice versa so that the resulting file is not corrupt.
If ValueAxis.UseLogarithmicScale is turned on, then this property represent the power of the maximum value in base 10 (or whatever base you've manually set). For instance, if this value is set to 5. Then with UseLogarithmicScale turned off, the resulting file will have a maximum value of 5. If UseLogarithmicScale is turned on, then the resulting file will have a maximum value of 100,000 (10 5).