3.21% is the change from 623 to 643
Calculation steps:
[( 643 - 623 ) ÷ 623] x 100 = 3.21%
Formula
Percentage change = [(643 - 623) / 623] x 100
Subtract the new number by the original number
643 - 623 = 20
20 ÷ 623 = 0.03210272873194221
0.03210272873194221 x 100 = 3.21%