-89.99% is the change from 839 to 84
Calculation steps:
[( 84 - 839 ) ÷ 839] x 100 = -89.99%
Formula
Percentage change = [(84 - 839) / 839] x 100
Subtract the new number by the original number
84 - 839 = -755
-755 ÷ 839 = -0.899880810488677
-0.899880810488677 x 100 = -89.99%