We have a column A (starting in cell A10) containing Customer IDs.
There's a column C containing different amounts associated with those Customer IDs.
We need to add total sums per Customer IDs at the last line of a listed Customer ID. See an example attached (number of Customers/rows keeps changing - is dynamic).
Then we need (per every CustomerID) to add a percentage amount field and highlight the top amounts which contribute to 80% or more of the all charged amounts (as shown in the sample).