-39.95% is the change from 428 to 257
Calculation steps:
[( 257 - 428 ) ÷ 428] x 100 = -39.95%
Formula
Percentage change = [(257 - 428) / 428] x 100
Subtract the new number by the original number
257 - 428 = -171
-171 ÷ 428 = -0.39953271028037385
-0.39953271028037385 x 100 = -39.95%