-98.91% is the change from 643 to 7
Calculation steps:
[( 7 - 643 ) ÷ 643] x 100 = -98.91%
Formula
Percentage change = [(7 - 643) / 643] x 100
Subtract the new number by the original number
7 - 643 = -636
-636 ÷ 643 = -0.9891135303265941
-0.9891135303265941 x 100 = -98.91%