Matrix Condition Formatting

Hi, 

I have a Matrix table and I want to have a conditional format on a percentage value.

The lowest value being red, centre value orange and maximum being green.

I have the formatting set to

Gradient

Values only (as I don't have the totals)

Format empty values as 0.

The table has 3 rows.

I think the problem is that my value has a NaN output as its trying to take a percentage of (0.00 / 0.00) - 0.00 measure below:

(appval_prev / appval_curr) - appval_curr

Any idea how to resolve please?