-3.91% is the change from 128 to 123
Calculation steps:
[( 123 - 128 ) ÷ 128] x 100 = -3.91%
Formula
Percentage change = [(123 - 128) / 128] x 100
Subtract the new number by the original number
123 - 128 = -5
-5 ÷ 128 = -0.0390625
-0.0390625 x 100 = -3.91%