-51.05% is the change from 858 to 420
Calculation steps:
[( 420 - 858 ) ÷ 858] x 100 = -51.05%
Formula
Percentage change = [(420 - 858) / 858] x 100
Subtract the new number by the original number
420 - 858 = -438
-438 ÷ 858 = -0.5104895104895105
-0.5104895104895105 x 100 = -51.05%