-69.61% is the change from 839 to 255
Calculation steps:
[( 255 - 839 ) ÷ 839] x 100 = -69.61%
Formula
Percentage change = [(255 - 839) / 839] x 100
Subtract the new number by the original number
255 - 839 = -584
-584 ÷ 839 = -0.6960667461263409
-0.6960667461263409 x 100 = -69.61%