-26.5% is the change from 668 to 491
Calculation steps:
[( 491 - 668 ) ÷ 668] x 100 = -26.5%
Formula
Percentage change = [(491 - 668) / 668] x 100
Subtract the new number by the original number
491 - 668 = -177
-177 ÷ 668 = -0.26497005988023953
-0.26497005988023953 x 100 = -26.5%