-0.29% is the change from 680 to 678
Calculation steps:
[( 678 - 680 ) ÷ 680] x 100 = -0.29%
Formula
Percentage change = [(678 - 680) / 680] x 100
Subtract the new number by the original number
678 - 680 = -2
-2 ÷ 680 = -0.0029411764705882353
-0.0029411764705882353 x 100 = -0.29%