-1.91% is the change from 681 to 668
Calculation steps:
[( 668 - 681 ) ÷ 681] x 100 = -1.91%
Formula
Percentage change = [(668 - 681) / 681] x 100
Subtract the new number by the original number
668 - 681 = -13
-13 ÷ 681 = -0.01908957415565345
-0.01908957415565345 x 100 = -1.91%