On Profit and Loss statement, how can I show a column with a percentage to the sales total for all the accounts ?

On the P&L statement, my client would like to see the percentage to the sales/revenue subtotal for each account and subtotal. For example, the cost of goods sold account needs to print a percentage compared to the revenue total $ (which is 100%). So if the total sales/revenue is $200,000 and the cost of goods account is $95,000, I want a column to print 47.5% next to the cost of goods sold account. My client wants to see what each account is as a percentage compared total sales/revenue on the profit and loss statement.

I haven't been able to find this on a standard report. Am I missing it or is this only possible after exporting to Excel?

Thanks,

Laura