-10.09% is the change from 991 to 891
Calculation steps:
[( 891 - 991 ) ÷ 991] x 100 = -10.09%
Formula
Percentage change = [(891 - 991) / 991] x 100
Subtract the new number by the original number
891 - 991 = -100
-100 ÷ 991 = -0.10090817356205853
-0.10090817356205853 x 100 = -10.09%