-0.15% is the change from 670 to 669
Calculation steps:
[( 669 - 670 ) ÷ 670] x 100 = -0.15%
Formula
Percentage change = [(669 - 670) / 670] x 100
Subtract the new number by the original number
669 - 670 = -1
-1 ÷ 670 = -0.0014925373134328358
-0.0014925373134328358 x 100 = -0.15%