-9.09% is the change from 891 to 810
Calculation steps:
[( 810 - 891 ) ÷ 891] x 100 = -9.09%
Formula
Percentage change = [(810 - 891) / 891] x 100
Subtract the new number by the original number
810 - 891 = -81
-81 ÷ 891 = -0.09090909090909091
-0.09090909090909091 x 100 = -9.09%