-17.81% is the change from 668 to 549
Calculation steps:
[( 549 - 668 ) ÷ 668] x 100 = -17.81%
Formula
Percentage change = [(549 - 668) / 668] x 100
Subtract the new number by the original number
549 - 668 = -119
-119 ÷ 668 = -0.1781437125748503
-0.1781437125748503 x 100 = -17.81%