-19.92% is the change from 502 to 402
Calculation steps:
[( 402 - 502 ) ÷ 502] x 100 = -19.92%
Formula
Percentage change = [(402 - 502) / 502] x 100
Subtract the new number by the original number
402 - 502 = -100
-100 ÷ 502 = -0.199203187250996
-0.199203187250996 x 100 = -19.92%