-83.88% is the change from 639 to 103
Calculation steps:
[( 103 - 639 ) ÷ 639] x 100 = -83.88%
Formula
Percentage change = [(103 - 639) / 639] x 100
Subtract the new number by the original number
103 - 639 = -536
-536 ÷ 639 = -0.838810641627543
-0.838810641627543 x 100 = -83.88%