-81.36% is the change from 531 to 99
Calculation steps:
[( 99 - 531 ) ÷ 531] x 100 = -81.36%
Formula
Percentage change = [(99 - 531) / 531] x 100
Subtract the new number by the original number
99 - 531 = -432
-432 ÷ 531 = -0.8135593220338984
-0.8135593220338984 x 100 = -81.36%