-31.03% is the change from 638 to 440
Calculation steps:
[( 440 - 638 ) ÷ 638] x 100 = -31.03%
Formula
Percentage change = [(440 - 638) / 638] x 100
Subtract the new number by the original number
440 - 638 = -198
-198 ÷ 638 = -0.3103448275862069
-0.3103448275862069 x 100 = -31.03%