-3.15% is the change from 858 to 831
Calculation steps:
[( 831 - 858 ) ÷ 858] x 100 = -3.15%
Formula
Percentage change = [(831 - 858) / 858] x 100
Subtract the new number by the original number
831 - 858 = -27
-27 ÷ 858 = -0.03146853146853147
-0.03146853146853147 x 100 = -3.15%