How do i go by decomposing actual and forecast with the given data using excel? I am confused as I have two products. Product A is seasonal and Product B has a growing trend. THE BOXED IS THE ACTUALS AND THE HIGHLIGHTED IS FORECAST

This year Next year in Units feb mar apr may jun jan feb mar apr may jun jul aug sep oct nov dec jan $8,000 $6,750 $7,500 $8,200 $9,000 $12,000 $13,000 $12,500 $13,250 $15,000 $25,000 $26,000 475 356 425 378 512 534 550 550 550 550 2000 2000 712 615 688 714 790 870 900 800 925 1000 1000 1000 600 600 600 Product A Product B 700 1500 700 1500 700 1500 1250 1250 1250 This year Next year in Units feb mar apr may jun jan feb mar apr may jun jul aug sep oct nov dec jan $8,000 $6,750 $7,500 $8,200 $9,000 $12,000 $13,000 $12,500 $13,250 $15,000 $25,000 $26,000 475 356 425 378 512 534 550 550 550 550 2000 2000 712 615 688 714 790 870 900 800 925 1000 1000 1000 600 600 600 Product A Product B 700 1500 700 1500 700 1500 1250 1250 1250