-0.4% is the change from 502 to 500
Calculation steps:
[( 500 - 502 ) ÷ 502] x 100 = -0.4%
Formula
Percentage change = [(500 - 502) / 502] x 100
Subtract the new number by the original number
500 - 502 = -2
-2 ÷ 502 = -0.00398406374501992
-0.00398406374501992 x 100 = -0.4%