7.74% is the change from 594 to 640
Calculation steps:
[( 640 - 594 ) ÷ 594] x 100 = 7.74%
Formula
Percentage change = [(640 - 594) / 594] x 100
Subtract the new number by the original number
640 - 594 = 46
46 ÷ 594 = 0.07744107744107744
0.07744107744107744 x 100 = 7.74%