-21.47% is the change from 326 to 256
Calculation steps:
[( 256 - 326 ) ÷ 326] x 100 = -21.47%
Formula
Percentage change = [(256 - 326) / 326] x 100
Subtract the new number by the original number
256 - 326 = -70
-70 ÷ 326 = -0.2147239263803681
-0.2147239263803681 x 100 = -21.47%