-24.85% is the change from 668 to 502
Calculation steps:
[( 502 - 668 ) ÷ 668] x 100 = -24.85%
Formula
Percentage change = [(502 - 668) / 668] x 100
Subtract the new number by the original number
502 - 668 = -166
-166 ÷ 668 = -0.24850299401197604
-0.24850299401197604 x 100 = -24.85%