-84.6% is the change from 831 to 128
Calculation steps:
[( 128 - 831 ) ÷ 831] x 100 = -84.6%
Formula
Percentage change = [(128 - 831) / 831] x 100
Subtract the new number by the original number
128 - 831 = -703
-703 ÷ 831 = -0.8459687123947052
-0.8459687123947052 x 100 = -84.6%