-98.99% is the change from 991 to 10
Calculation steps:
[( 10 - 991 ) ÷ 991] x 100 = -98.99%
Formula
Percentage change = [(10 - 991) / 991] x 100
Subtract the new number by the original number
10 - 991 = -981
-981 ÷ 991 = -0.9899091826437941
-0.9899091826437941 x 100 = -98.99%