-81.76% is the change from 499 to 91
Calculation steps:
[( 91 - 499 ) ÷ 499] x 100 = -81.76%
Formula
Percentage change = [(91 - 499) / 499] x 100
Subtract the new number by the original number
91 - 499 = -408
-408 ÷ 499 = -0.8176352705410822
-0.8176352705410822 x 100 = -81.76%