-55.56% is the change from 18 to 8
Calculation steps:
[( 8 - 18 ) ÷ 18] x 100 = -55.56%
Formula
Percentage change = [(8 - 18) / 18] x 100
Subtract the new number by the original number
8 - 18 = -10
-10 ÷ 18 = -0.5555555555555556
-0.5555555555555556 x 100 = -55.56%