-11.5% is the change from 939 to 831
Calculation steps:
[( 831 - 939 ) ÷ 939] x 100 = -11.5%
Formula
Percentage change = [(831 - 939) / 939] x 100
Subtract the new number by the original number
831 - 939 = -108
-108 ÷ 939 = -0.11501597444089456
-0.11501597444089456 x 100 = -11.5%