-6.55% is the change from 687 to 642
Calculation steps:
[( 642 - 687 ) ÷ 687] x 100 = -6.55%
Formula
Percentage change = [(642 - 687) / 687] x 100
Subtract the new number by the original number
642 - 687 = -45
-45 ÷ 687 = -0.06550218340611354
-0.06550218340611354 x 100 = -6.55%