6.49% is the change from 601 to 640
Calculation steps:
[( 640 - 601 ) ÷ 601] x 100 = 6.49%
Formula
Percentage change = [(640 - 601) / 601] x 100
Subtract the new number by the original number
640 - 601 = 39
39 ÷ 601 = 0.064891846921797
0.064891846921797 x 100 = 6.49%