3.27% is the change from 643 to 664
Calculation steps:
[( 664 - 643 ) ÷ 643] x 100 = 3.27%
Formula
Percentage change = [(664 - 643) / 643] x 100
Subtract the new number by the original number
664 - 643 = 21
21 ÷ 643 = 0.03265940902021773
0.03265940902021773 x 100 = 3.27%