-1.8% is the change from 668 to 656
Calculation steps:
[( 656 - 668 ) ÷ 668] x 100 = -1.8%
Formula
Percentage change = [(656 - 668) / 668] x 100
Subtract the new number by the original number
656 - 668 = -12
-12 ÷ 668 = -0.017964071856287425
-0.017964071856287425 x 100 = -1.8%