-80.28% is the change from 502 to 99
Calculation steps:
[( 99 - 502 ) ÷ 502] x 100 = -80.28%
Formula
Percentage change = [(99 - 502) / 502] x 100
Subtract the new number by the original number
99 - 502 = -403
-403 ÷ 502 = -0.8027888446215139
-0.8027888446215139 x 100 = -80.28%