-10.16% is the change from 128 to 115
Calculation steps:
[( 115 - 128 ) ÷ 128] x 100 = -10.16%
Formula
Percentage change = [(115 - 128) / 128] x 100
Subtract the new number by the original number
115 - 128 = -13
-13 ÷ 128 = -0.1015625
-0.1015625 x 100 = -10.16%