-89.89% is the change from 979 to 99
Calculation steps:
[( 99 - 979 ) ÷ 979] x 100 = -89.89%
Formula
Percentage change = [(99 - 979) / 979] x 100
Subtract the new number by the original number
99 - 979 = -880
-880 ÷ 979 = -0.898876404494382
-0.898876404494382 x 100 = -89.89%