3.01% is the change from 664 to 684
Calculation steps:
[( 684 - 664 ) ÷ 664] x 100 = 3.01%
Formula
Percentage change = [(684 - 664) / 664] x 100
Subtract the new number by the original number
684 - 664 = 20
20 ÷ 664 = 0.030120481927710843
0.030120481927710843 x 100 = 3.01%