-39.39% is the change from 858 to 520
Calculation steps:
[( 520 - 858 ) ÷ 858] x 100 = -39.39%
Formula
Percentage change = [(520 - 858) / 858] x 100
Subtract the new number by the original number
520 - 858 = -338
-338 ÷ 858 = -0.3939393939393939
-0.3939393939393939 x 100 = -39.39%