3.27% is the change from 642 to 663
Calculation steps:
[( 663 - 642 ) ÷ 642] x 100 = 3.27%
Formula
Percentage change = [(663 - 642) / 642] x 100
Subtract the new number by the original number
663 - 642 = 21
21 ÷ 642 = 0.03271028037383177
0.03271028037383177 x 100 = 3.27%