I have a chart with a primary and secondary axis.

Values for the primary axis range from 0 to 260, values for the secondary
axis range from -50% to 50%.

I would like to have the zeros on both axis line up, so that the negative
percentages on the secondary axis are clearly identifiable. I can't find a
way to do it.

In the default chart, the x axis crosses the primary y-axis at 0, but the 0
on the secondary y-axis is at approximately the same height as the value 50
on the primary axis.

Please help!
Astrid