0.6% is the change from 664 to 668
Calculation steps:
[( 668 - 664 ) ÷ 664] x 100 = 0.6%
Formula
Percentage change = [(668 - 664) / 664] x 100
Subtract the new number by the original number
668 - 664 = 4
4 ÷ 664 = 0.006024096385542169
0.006024096385542169 x 100 = 0.6%