-1.47% is the change from 680 to 670
Calculation steps:
[( 670 - 680 ) ÷ 680] x 100 = -1.47%
Formula
Percentage change = [(670 - 680) / 680] x 100
Subtract the new number by the original number
670 - 680 = -10
-10 ÷ 680 = -0.014705882352941176
-0.014705882352941176 x 100 = -1.47%