-69.49% is the change from 839 to 256
Calculation steps:
[( 256 - 839 ) ÷ 839] x 100 = -69.49%
Formula
Percentage change = [(256 - 839) / 839] x 100
Subtract the new number by the original number
256 - 839 = -583
-583 ÷ 839 = -0.6948748510131109
-0.6948748510131109 x 100 = -69.49%