-39.48% is the change from 423 to 256
Calculation steps:
[( 256 - 423 ) ÷ 423] x 100 = -39.48%
Formula
Percentage change = [(256 - 423) / 423] x 100
Subtract the new number by the original number
256 - 423 = -167
-167 ÷ 423 = -0.3947990543735225
-0.3947990543735225 x 100 = -39.48%