-90.1% is the change from 818 to 81
Calculation steps:
[( 81 - 818 ) ÷ 818] x 100 = -90.1%
Formula
Percentage change = [(81 - 818) / 818] x 100
Subtract the new number by the original number
81 - 818 = -737
-737 ÷ 818 = -0.9009779951100244
-0.9009779951100244 x 100 = -90.1%