-63.79% is the change from 638 to 231
Calculation steps:
[( 231 - 638 ) ÷ 638] x 100 = -63.79%
Formula
Percentage change = [(231 - 638) / 638] x 100
Subtract the new number by the original number
231 - 638 = -407
-407 ÷ 638 = -0.6379310344827587
-0.6379310344827587 x 100 = -63.79%