Stop Charts Changing Size when Inputs Change

Is there a way of stopping my charts from changing size when I swap two of the the data inputs? Swapping two inputs D7 and D8 means that the borders of the chart change to accommodate an extra number on the Y axis, i.e. from 100 to 1000. This then increases the width of the chart. I have locked all 4 charts and reversed the D7 and D8 inputs but it doesn't stop the charts from changing size as can be seen in the second image and the grey "crosshair" in the middle that divides the 4 charts.

Cheers!