-97.02% is the change from 638 to 19
Calculation steps:
[( 19 - 638 ) ÷ 638] x 100 = -97.02%
Formula
Percentage change = [(19 - 638) / 638] x 100
Subtract the new number by the original number
19 - 638 = -619
-619 ÷ 638 = -0.9702194357366771
-0.9702194357366771 x 100 = -97.02%