2.69% is the change from 670 to 688
Calculation steps:
[( 688 - 670 ) ÷ 670] x 100 = 2.69%
Formula
Percentage change = [(688 - 670) / 670] x 100
Subtract the new number by the original number
688 - 670 = 18
18 ÷ 670 = 0.026865671641791045
0.026865671641791045 x 100 = 2.69%