-69.52% is the change from 420 to 128
Calculation steps:
[( 128 - 420 ) ÷ 420] x 100 = -69.52%
Formula
Percentage change = [(128 - 420) / 420] x 100
Subtract the new number by the original number
128 - 420 = -292
-292 ÷ 420 = -0.6952380952380952
-0.6952380952380952 x 100 = -69.52%