-97.51% is the change from 643 to 16
Calculation steps:
[( 16 - 643 ) ÷ 643] x 100 = -97.51%
Formula
Percentage change = [(16 - 643) / 643] x 100
Subtract the new number by the original number
16 - 643 = -627
-627 ÷ 643 = -0.9751166407465007
-0.9751166407465007 x 100 = -97.51%