-82.63% is the change from 800 to 139
Calculation steps:
[( 139 - 800 ) ÷ 800] x 100 = -82.63%
Formula
Percentage change = [(139 - 800) / 800] x 100
Subtract the new number by the original number
139 - 800 = -661
-661 ÷ 800 = -0.82625
-0.82625 x 100 = -82.63%