-81.53% is the change from 839 to 155
Calculation steps:
[( 155 - 839 ) ÷ 839] x 100 = -81.53%
Formula
Percentage change = [(155 - 839) / 839] x 100
Subtract the new number by the original number
155 - 839 = -684
-684 ÷ 839 = -0.8152562574493445
-0.8152562574493445 x 100 = -81.53%