-34.36% is the change from 390 to 256
Calculation steps:
[( 256 - 390 ) ÷ 390] x 100 = -34.36%
Formula
Percentage change = [(256 - 390) / 390] x 100
Subtract the new number by the original number
256 - 390 = -134
-134 ÷ 390 = -0.3435897435897436
-0.3435897435897436 x 100 = -34.36%