-96.39% is the change from 638 to 23
Calculation steps:
[( 23 - 638 ) ÷ 638] x 100 = -96.39%
Formula
Percentage change = [(23 - 638) / 638] x 100
Subtract the new number by the original number
23 - 638 = -615
-615 ÷ 638 = -0.9639498432601881
-0.9639498432601881 x 100 = -96.39%