-20.52% is the change from 502 to 399
Calculation steps:
[( 399 - 502 ) ÷ 502] x 100 = -20.52%
Formula
Percentage change = [(399 - 502) / 502] x 100
Subtract the new number by the original number
399 - 502 = -103
-103 ÷ 502 = -0.2051792828685259
-0.2051792828685259 x 100 = -20.52%