Create variance slider?

The attached sample file is a very small example of a data set I am working with.

You will see I've used a combination of a scroll bar and conditional formatting to created a level of interactivity with the data. (This technique was thanks to one of you wonderful folks here on the forum.) As you move the slider, cells whose values are below the slider value disappear (via having their text color changed to white in the conditional formatting.)

This technique is really great. I'd like to add another slider to highlight the amount of variance from month-to-month for each group.

My actual spreadsheet is much larger than this and I really cannot add new columns to hold variance values. Another challenge is the way the data is laid out with Jan through Jun being repeated.

I want another slider that will be 0% to 100%, and it will color in red those values whose variance from the previous month are above the current slider value.

Since there is never a "previous month" for the Jan values to be compared against, they should never get colored.

I hope I've described this well enough for someone to be able to help me.