-56.11% is the change from 638 to 280
Calculation steps:
[( 280 - 638 ) ÷ 638] x 100 = -56.11%
Formula
Percentage change = [(280 - 638) / 638] x 100
Subtract the new number by the original number
280 - 638 = -358
-358 ÷ 638 = -0.5611285266457681
-0.5611285266457681 x 100 = -56.11%