-19.72% is the change from 502 to 403
Calculation steps:
[( 403 - 502 ) ÷ 502] x 100 = -19.72%
Formula
Percentage change = [(403 - 502) / 502] x 100
Subtract the new number by the original number
403 - 502 = -99
-99 ÷ 502 = -0.19721115537848605
-0.19721115537848605 x 100 = -19.72%