-3.94% is the change from 508 to 488
Calculation steps:
[( 488 - 508 ) ÷ 508] x 100 = -3.94%
Formula
Percentage change = [(488 - 508) / 508] x 100
Subtract the new number by the original number
488 - 508 = -20
-20 ÷ 508 = -0.03937007874015748
-0.03937007874015748 x 100 = -3.94%