-2.81% is the change from 855 to 831
Calculation steps:
[( 831 - 855 ) ÷ 855] x 100 = -2.81%
Formula
Percentage change = [(831 - 855) / 855] x 100
Subtract the new number by the original number
831 - 855 = -24
-24 ÷ 855 = -0.028070175438596492
-0.028070175438596492 x 100 = -2.81%