-97.28% is the change from 991 to 27
Calculation steps:
[( 27 - 991 ) ÷ 991] x 100 = -97.28%
Formula
Percentage change = [(27 - 991) / 991] x 100
Subtract the new number by the original number
27 - 991 = -964
-964 ÷ 991 = -0.9727547931382442
-0.9727547931382442 x 100 = -97.28%