-50.93% is the change from 856 to 420
Calculation steps:
[( 420 - 856 ) ÷ 856] x 100 = -50.93%
Formula
Percentage change = [(420 - 856) / 856] x 100
Subtract the new number by the original number
420 - 856 = -436
-436 ÷ 856 = -0.5093457943925234
-0.5093457943925234 x 100 = -50.93%