Custom range on visuals

Hello,

Hoping i'm explaining this correctly but i require some assiastane on a visual and setting the ranges. The visual displays the Maximum number for each month. 

I have a visual that interacts with a slicer however I need the range on the Y Axis to display a minimum and maximum of +5 either side of what is shown on the visual. This is because the increase/decrease from month to month looks worse than it is, when really it is only -1 or +2. Because it is showing the maximum number, even if I make the visual bigger, the Y Axis stays the same.

The issue with setting the range, for example to minimum 75 and maximum 90, is that when I select another option from the slicer, the line completely disappears because the value is less than 75.

No Line.

Is there anyway to custom the range to show +5 / -5 on the Y Axis, of say, for example the average of the value of the numbers across the months? For example if the average value across the months is 83 for the option I have selected on the slicer, the Y Axis will show 78 - 88. Or any other way to achieve this, doesn't necessarily have to be based on the average, could be based on the min / max number.

Hope this makes sense and as always appreciate any help provided 🙂

Thanks,

Josh