-80.08% is the change from 497 to 99
Calculation steps:
[( 99 - 497 ) ÷ 497] x 100 = -80.08%
Formula
Percentage change = [(99 - 497) / 497] x 100
Subtract the new number by the original number
99 - 497 = -398
-398 ÷ 497 = -0.8008048289738431
-0.8008048289738431 x 100 = -80.08%