-6.47% is the change from 680 to 636
Calculation steps:
[( 636 - 680 ) ÷ 680] x 100 = -6.47%
Formula
Percentage change = [(636 - 680) / 680] x 100
Subtract the new number by the original number
636 - 680 = -44
-44 ÷ 680 = -0.06470588235294118
-0.06470588235294118 x 100 = -6.47%