By default, the biggest value in the chart will have a full bar from bottom to top.
Is there a way to get some space between the top of the diagram and the maximum value? I wanted to have a standard zoom of 90% or something like this, but zooming out any further is not possible.
Yes, this is possible using axis MaximumOffset property. For example:
Chart1.Axes.Left.MaximumOffset:=25;