-61.72% is the change from 128 to 49
Calculation steps:
[( 49 - 128 ) ÷ 128] x 100 = -61.72%
Formula
Percentage change = [(49 - 128) / 128] x 100
Subtract the new number by the original number
49 - 128 = -79
-79 ÷ 128 = -0.6171875
-0.6171875 x 100 = -61.72%