-99.09% is the change from 989 to 9
Calculation steps:
[( 9 - 989 ) ÷ 989] x 100 = -99.09%
Formula
Percentage change = [(9 - 989) / 989] x 100
Subtract the new number by the original number
9 - 989 = -980
-980 ÷ 989 = -0.9908998988877654
-0.9908998988877654 x 100 = -99.09%