How to achieve this below kind of subtotal of every 2 rows beneath them? Price Count Total Price Product A 1 2 3 Product B 1 2 3 Subtotal A+B A1+B1 A2+B2 A3+B3 Product C 1 2 3 Product D 1 2 3 Subtotal C+D C1+D1 C2+D2 C3+D3 Product E 1 2 3 Product F 1...