-6.41% is the change from 686 to 642
Calculation steps:
[( 642 - 686 ) ÷ 686] x 100 = -6.41%
Formula
Percentage change = [(642 - 686) / 686] x 100
Subtract the new number by the original number
642 - 686 = -44
-44 ÷ 686 = -0.0641399416909621
-0.0641399416909621 x 100 = -6.41%