I have a Nevron bar chart that displays the value for each datapoint in each bar.

The problem that I have is that some labels in the bar have a low value and the label displays below the x axis while the other larger values display fine in their bar.

I set the arrowlength like so:
series.DataLabelStyle.ArrowLength = new NLength(-10);  //this displays the larger values fine

Is there a way to set the ArrowLength based on the value that is going to be shown in the bar? Like so:

If (value <= 50)
{
series.DataLabelStyle.ArrowLength = new NLength(+20)
}
else
{
series.DataLabelStyle.ArrowLength = new NLength(-10)
}