-95.3% is the change from 638 to 30
Calculation steps:
[( 30 - 638 ) ÷ 638] x 100 = -95.3%
Formula
Percentage change = [(30 - 638) / 638] x 100
Subtract the new number by the original number
30 - 638 = -608
-608 ÷ 638 = -0.9529780564263323
-0.9529780564263323 x 100 = -95.3%