8.11% is the change from 592 to 640
Calculation steps:
[( 640 - 592 ) ÷ 592] x 100 = 8.11%
Formula
Percentage change = [(640 - 592) / 592] x 100
Subtract the new number by the original number
640 - 592 = 48
48 ÷ 592 = 0.08108108108108109
0.08108108108108109 x 100 = 8.11%