-98.9% is the change from 818 to 9
Calculation steps:
[( 9 - 818 ) ÷ 818] x 100 = -98.9%
Formula
Percentage change = [(9 - 818) / 818] x 100
Subtract the new number by the original number
9 - 818 = -809
-809 ÷ 818 = -0.988997555012225
-0.988997555012225 x 100 = -98.9%