-16.82% is the change from 999 to 831
Calculation steps:
[( 831 - 999 ) ÷ 999] x 100 = -16.82%
Formula
Percentage change = [(831 - 999) / 999] x 100
Subtract the new number by the original number
831 - 999 = -168
-168 ÷ 999 = -0.16816816816816818
-0.16816816816816818 x 100 = -16.82%