-90.35% is the change from 829 to 80
Calculation steps:
[( 80 - 829 ) ÷ 829] x 100 = -90.35%
Formula
Percentage change = [(80 - 829) / 829] x 100
Subtract the new number by the original number
80 - 829 = -749
-749 ÷ 829 = -0.9034981905910736
-0.9034981905910736 x 100 = -90.35%