-91.2% is the change from 909 to 80
Calculation steps:
[( 80 - 909 ) ÷ 909] x 100 = -91.2%
Formula
Percentage change = [(80 - 909) / 909] x 100
Subtract the new number by the original number
80 - 909 = -829
-829 ÷ 909 = -0.911991199119912
-0.911991199119912 x 100 = -91.2%