4.21% is the change from 641 to 668
Calculation steps:
[( 668 - 641 ) ÷ 641] x 100 = 4.21%
Formula
Percentage change = [(668 - 641) / 641] x 100
Subtract the new number by the original number
668 - 641 = 27
27 ÷ 641 = 0.0421216848673947
0.0421216848673947 x 100 = 4.21%