-98.75% is the change from 642 to 8
Calculation steps:
[( 8 - 642 ) ÷ 642] x 100 = -98.75%
Formula
Percentage change = [(8 - 642) / 642] x 100
Subtract the new number by the original number
8 - 642 = -634
-634 ÷ 642 = -0.9875389408099688
-0.9875389408099688 x 100 = -98.75%