-82.92% is the change from 638 to 109
Calculation steps:
[( 109 - 638 ) ÷ 638] x 100 = -82.92%
Formula
Percentage change = [(109 - 638) / 638] x 100
Subtract the new number by the original number
109 - 638 = -529
-529 ÷ 638 = -0.829153605015674
-0.829153605015674 x 100 = -82.92%