-89.48% is the change from 770 to 81
Calculation steps:
[( 81 - 770 ) ÷ 770] x 100 = -89.48%
Formula
Percentage change = [(81 - 770) / 770] x 100
Subtract the new number by the original number
81 - 770 = -689
-689 ÷ 770 = -0.8948051948051948
-0.8948051948051948 x 100 = -89.48%