-99.38% is the change from 643 to 4
Calculation steps:
[( 4 - 643 ) ÷ 643] x 100 = -99.38%
Formula
Percentage change = [(4 - 643) / 643] x 100
Subtract the new number by the original number
4 - 643 = -639
-639 ÷ 643 = -0.9937791601866252
-0.9937791601866252 x 100 = -99.38%