2.99% is the change from 668 to 688
Calculation steps:
[( 688 - 668 ) ÷ 668] x 100 = 2.99%
Formula
Percentage change = [(688 - 668) / 668] x 100
Subtract the new number by the original number
688 - 668 = 20
20 ÷ 668 = 0.029940119760479042
0.029940119760479042 x 100 = 2.99%