9.78% is the change from 583 to 640
Calculation steps:
[( 640 - 583 ) ÷ 583] x 100 = 9.78%
Formula
Percentage change = [(640 - 583) / 583] x 100
Subtract the new number by the original number
640 - 583 = 57
57 ÷ 583 = 0.09777015437392796
0.09777015437392796 x 100 = 9.78%