-0.75% is the change from 671 to 666
Calculation steps:
[( 666 - 671 ) ÷ 671] x 100 = -0.75%
Formula
Percentage change = [(666 - 671) / 671] x 100
Subtract the new number by the original number
666 - 671 = -5
-5 ÷ 671 = -0.007451564828614009
-0.007451564828614009 x 100 = -0.75%