-9.86% is the change from 284 to 256
Calculation steps:
[( 256 - 284 ) ÷ 284] x 100 = -9.86%
Formula
Percentage change = [(256 - 284) / 284] x 100
Subtract the new number by the original number
256 - 284 = -28
-28 ÷ 284 = -0.09859154929577464
-0.09859154929577464 x 100 = -9.86%