-98.7% is the change from 615 to 8
Calculation steps:
[( 8 - 615 ) ÷ 615] x 100 = -98.7%
Formula
Percentage change = [(8 - 615) / 615] x 100
Subtract the new number by the original number
8 - 615 = -607
-607 ÷ 615 = -0.9869918699186991
-0.9869918699186991 x 100 = -98.7%