-69.6% is the change from 421 to 128
Calculation steps:
[( 128 - 421 ) ÷ 421] x 100 = -69.6%
Formula
Percentage change = [(128 - 421) / 421] x 100
Subtract the new number by the original number
128 - 421 = -293
-293 ÷ 421 = -0.6959619952494062
-0.6959619952494062 x 100 = -69.6%