-97.9% is the change from 858 to 18
Calculation steps:
[( 18 - 858 ) ÷ 858] x 100 = -97.9%
Formula
Percentage change = [(18 - 858) / 858] x 100
Subtract the new number by the original number
18 - 858 = -840
-840 ÷ 858 = -0.9790209790209791
-0.9790209790209791 x 100 = -97.9%