-49.82% is the change from 839 to 421
Calculation steps:
[( 421 - 839 ) ÷ 839] x 100 = -49.82%
Formula
Percentage change = [(421 - 839) / 839] x 100
Subtract the new number by the original number
421 - 839 = -418
-418 ÷ 839 = -0.49821215733015495
-0.49821215733015495 x 100 = -49.82%