-39.37% is the change from 508 to 308
Calculation steps:
[( 308 - 508 ) ÷ 508] x 100 = -39.37%
Formula
Percentage change = [(308 - 508) / 508] x 100
Subtract the new number by the original number
308 - 508 = -200
-200 ÷ 508 = -0.3937007874015748
-0.3937007874015748 x 100 = -39.37%