-3.05% is the change from 688 to 667
Calculation steps:
[( 667 - 688 ) ÷ 688] x 100 = -3.05%
Formula
Percentage change = [(667 - 688) / 688] x 100
Subtract the new number by the original number
667 - 688 = -21
-21 ÷ 688 = -0.030523255813953487
-0.030523255813953487 x 100 = -3.05%