-33.07% is the change from 638 to 427
Calculation steps:
[( 427 - 638 ) ÷ 638] x 100 = -33.07%
Formula
Percentage change = [(427 - 638) / 638] x 100
Subtract the new number by the original number
427 - 638 = -211
-211 ÷ 638 = -0.33072100313479624
-0.33072100313479624 x 100 = -33.07%