-91.22% is the change from 991 to 87
Calculation steps:
[( 87 - 991 ) ÷ 991] x 100 = -91.22%
Formula
Percentage change = [(87 - 991) / 991] x 100
Subtract the new number by the original number
87 - 991 = -904
-904 ÷ 991 = -0.9122098890010091
-0.9122098890010091 x 100 = -91.22%