Zero-centred x-axis on head-to-head style bar chart

[Matt Bradley-Roberts]

Looking for some help please.

I've created a head-to-head style bar chart (see below) and I want the zero (x-axis) to always be centred, even if the values are heavily skewed in the positive or negative (as below the positive value is nearly double the negative).

Any help on how to achieve this would be gratefully accepted!

Let me know if you need a code snippet of what I've done so far.

Many thanks.