Remaining amount of top x

Hello,

I have a quey where I want to show the top % based on a certain amount. On top of the result I have the total, then the detail list of top x. I would like to see also a line with the difference "others" between the total amount and the total top x (instead of being obliged to calcule it myself)

Example Top 4 overdue amounts

Total Overdue amount: 500

Customer 1 200

Customer 2 100

Customer 3 80

Customer 4 50

Others 70

Thanks

Francis