-94.01% is the change from 668 to 40
Calculation steps:
[( 40 - 668 ) ÷ 668] x 100 = -94.01%
Formula
Percentage change = [(40 - 668) / 668] x 100
Subtract the new number by the original number
40 - 668 = -628
-628 ÷ 668 = -0.9401197604790419
-0.9401197604790419 x 100 = -94.01%