-82.91% is the change from 831 to 142
Calculation steps:
[( 142 - 831 ) ÷ 831] x 100 = -82.91%
Formula
Percentage change = [(142 - 831) / 831] x 100
Subtract the new number by the original number
142 - 831 = -689
-689 ÷ 831 = -0.8291215403128761
-0.8291215403128761 x 100 = -82.91%