-81.78% is the change from 439 to 80
Calculation steps:
[( 80 - 439 ) ÷ 439] x 100 = -81.78%
Formula
Percentage change = [(80 - 439) / 439] x 100
Subtract the new number by the original number
80 - 439 = -359
-359 ÷ 439 = -0.8177676537585421
-0.8177676537585421 x 100 = -81.78%