-90.91% is the change from 891 to 81
Calculation steps:
[( 81 - 891 ) ÷ 891] x 100 = -90.91%
Formula
Percentage change = [(81 - 891) / 891] x 100
Subtract the new number by the original number
81 - 891 = -810
-810 ÷ 891 = -0.9090909090909091
-0.9090909090909091 x 100 = -90.91%