-15.91% is the change from 641 to 539
Calculation steps:
[( 539 - 641 ) ÷ 641] x 100 = -15.91%
Formula
Percentage change = [(539 - 641) / 641] x 100
Subtract the new number by the original number
539 - 641 = -102
-102 ÷ 641 = -0.15912636505460218
-0.15912636505460218 x 100 = -15.91%