-93.93% is the change from 642 to 39
Calculation steps:
[( 39 - 642 ) ÷ 642] x 100 = -93.93%
Formula
Percentage change = [(39 - 642) / 642] x 100
Subtract the new number by the original number
39 - 642 = -603
-603 ÷ 642 = -0.9392523364485982
-0.9392523364485982 x 100 = -93.93%