-99.06% is the change from 638 to 6
Calculation steps:
[( 6 - 638 ) ÷ 638] x 100 = -99.06%
Formula
Percentage change = [(6 - 638) / 638] x 100
Subtract the new number by the original number
6 - 638 = -632
-632 ÷ 638 = -0.9905956112852664
-0.9905956112852664 x 100 = -99.06%