Percentage of a count data in Pivot table
 

I have a pivot table pulled from a database. The database has Invoice
number, line number, product number, customer number and operator code
taking the order. It is possible in a given day the order was modified by
another operator to add-on products ordered by a customer. In my pivot table
I am counting the number of lines for each customer by the operator code.
This was easy. I want to see % of lines by operator code for each customer
and not as % of row or coulmn. I am willing to add a field to my data to
achieve % of line by operator. How to write a formula?