-99.8% is the change from 502 to 1
Calculation steps:
[( 1 - 502 ) ÷ 502] x 100 = -99.8%
Formula
Percentage change = [(1 - 502) / 502] x 100
Subtract the new number by the original number
1 - 502 = -501
-501 ÷ 502 = -0.99800796812749
-0.99800796812749 x 100 = -99.8%