-9.23% is the change from 639 to 580
Calculation steps:
[( 580 - 639 ) ÷ 639] x 100 = -9.23%
Formula
Percentage change = [(580 - 639) / 639] x 100
Subtract the new number by the original number
580 - 639 = -59
-59 ÷ 639 = -0.09233176838810642
-0.09233176838810642 x 100 = -9.23%