-7.51% is the change from 639 to 591
Calculation steps:
[( 591 - 639 ) ÷ 639] x 100 = -7.51%
Formula
Percentage change = [(591 - 639) / 639] x 100
Subtract the new number by the original number
591 - 639 = -48
-48 ÷ 639 = -0.07511737089201878
-0.07511737089201878 x 100 = -7.51%