-93.45% is the change from 641 to 42
Calculation steps:
[( 42 - 641 ) ÷ 641] x 100 = -93.45%
Formula
Percentage change = [(42 - 641) / 641] x 100
Subtract the new number by the original number
42 - 641 = -599
-599 ÷ 641 = -0.9344773790951638
-0.9344773790951638 x 100 = -93.45%