-91.11% is the change from 911 to 81
Calculation steps:
[( 81 - 911 ) ÷ 911] x 100 = -91.11%
Formula
Percentage change = [(81 - 911) / 911] x 100
Subtract the new number by the original number
81 - 911 = -830
-830 ÷ 911 = -0.9110867178924259
-0.9110867178924259 x 100 = -91.11%