-0.91% is the change from 990 to 981
Calculation steps:
[( 981 - 990 ) ÷ 990] x 100 = -0.91%
Formula
Percentage change = [(981 - 990) / 990] x 100
Subtract the new number by the original number
981 - 990 = -9
-9 ÷ 990 = -0.00909090909090909
-0.00909090909090909 x 100 = -0.91%