-98.9% is the change from 635 to 7
Calculation steps:
[( 7 - 635 ) ÷ 635] x 100 = -98.9%
Formula
Percentage change = [(7 - 635) / 635] x 100
Subtract the new number by the original number
7 - 635 = -628
-628 ÷ 635 = -0.988976377952756
-0.988976377952756 x 100 = -98.9%