-90.59% is the change from 861 to 81
Calculation steps:
[( 81 - 861 ) ÷ 861] x 100 = -90.59%
Formula
Percentage change = [(81 - 861) / 861] x 100
Subtract the new number by the original number
81 - 861 = -780
-780 ÷ 861 = -0.9059233449477352
-0.9059233449477352 x 100 = -90.59%