-97.55% is the change from 858 to 21
Calculation steps:
[( 21 - 858 ) ÷ 858] x 100 = -97.55%
Formula
Percentage change = [(21 - 858) / 858] x 100
Subtract the new number by the original number
21 - 858 = -837
-837 ÷ 858 = -0.9755244755244755
-0.9755244755244755 x 100 = -97.55%