-98.9% is the change from 816 to 9
Calculation steps:
[( 9 - 816 ) ÷ 816] x 100 = -98.9%
Formula
Percentage change = [(9 - 816) / 816] x 100
Subtract the new number by the original number
9 - 816 = -807
-807 ÷ 816 = -0.9889705882352942
-0.9889705882352942 x 100 = -98.9%