3.61% is the change from 638 to 661
Calculation steps:
[( 661 - 638 ) ÷ 638] x 100 = 3.61%
Formula
Percentage change = [(661 - 638) / 638] x 100
Subtract the new number by the original number
661 - 638 = 23
23 ÷ 638 = 0.03605015673981191
0.03605015673981191 x 100 = 3.61%