2.73% is the change from 623 to 640
Calculation steps:
[( 640 - 623 ) ÷ 623] x 100 = 2.73%
Formula
Percentage change = [(640 - 623) / 623] x 100
Subtract the new number by the original number
640 - 623 = 17
17 ÷ 623 = 0.027287319422150885
0.027287319422150885 x 100 = 2.73%