-0.9% is the change from 669 to 663
Calculation steps:
[( 663 - 669 ) ÷ 669] x 100 = -0.9%
Formula
Percentage change = [(663 - 669) / 669] x 100
Subtract the new number by the original number
663 - 669 = -6
-6 ÷ 669 = -0.008968609865470852
-0.008968609865470852 x 100 = -0.9%