-93.69% is the change from 666 to 42
Calculation steps:
[( 42 - 666 ) ÷ 666] x 100 = -93.69%
Formula
Percentage change = [(42 - 666) / 666] x 100
Subtract the new number by the original number
42 - 666 = -624
-624 ÷ 666 = -0.9369369369369369
-0.9369369369369369 x 100 = -93.69%