-83.4% is the change from 771 to 128
Calculation steps:
[( 128 - 771 ) ÷ 771] x 100 = -83.4%
Formula
Percentage change = [(128 - 771) / 771] x 100
Subtract the new number by the original number
128 - 771 = -643
-643 ÷ 771 = -0.833981841763943
-0.833981841763943 x 100 = -83.4%