-86.25% is the change from 80 to 11
Calculation steps:
[( 11 - 80 ) ÷ 80] x 100 = -86.25%
Formula
Percentage change = [(11 - 80) / 80] x 100
Subtract the new number by the original number
11 - 80 = -69
-69 ÷ 80 = -0.8625
-0.8625 x 100 = -86.25%
Example