-90.13% is the change from 800 to 79
Calculation steps:
[( 79 - 800 ) ÷ 800] x 100 = -90.13%
Formula
Percentage change = [(79 - 800) / 800] x 100
Subtract the new number by the original number
79 - 800 = -721
-721 ÷ 800 = -0.90125
-0.90125 x 100 = -90.13%