Figuring out scales based on a % value

Hi!!

So I have a question and I am trying to figure out how to word it best so that its hopefully possible.

Here is my issue:

I have a few charts like this:

1.PNG

And using the VBA code found here: https://exceloffthegrid.com/chart-axis-min-mix/ , I am able to scale my primary and secondary axes the way I want them to be scaled.

The way I want the scaling to be done is the max value of the Light Blue shaded area to align with 100% from the primary axis

When the max % is 100%, its super easy, all I have to do is set the scale for the max Secondary axis value to be the MAX value of the row in which this data comes from (shown in the first image) and the macro takes care of the rest.

So my ask, and my issue, is how do I do this if the max % in the primary axis is over 100%? Example shown below:
1.PNG

What I did for this current snip was a whole bunch of guess-and-check plugging numbers into the Max Secondary axis and finally found the sweet spot that aligned the Light Blue with 100%

If this is possible, I would prefer to have some function statement that figures that scale out automatically, so every month I don't have to go back and guess-and-check again.

Does this make sense? I feel like there's probably a better way to explain but I cannot for the life of me figure it out, but anyways I am really hoping this is possible!

Please let me know if you have any suggestions!!! Thank you so mcuh!

Thank you so much!

Apologies on the late response but I really appreciate the help