-93.5% is the change from 646 to 42
Calculation steps:
[( 42 - 646 ) ÷ 646] x 100 = -93.5%
Formula
Percentage change = [(42 - 646) / 646] x 100
Subtract the new number by the original number
42 - 646 = -604
-604 ÷ 646 = -0.934984520123839
-0.934984520123839 x 100 = -93.5%