3.37% is the change from 624 to 645
Calculation steps:
[( 645 - 624 ) ÷ 624] x 100 = 3.37%
Formula
Percentage change = [(645 - 624) / 624] x 100
Subtract the new number by the original number
645 - 624 = 21
21 ÷ 624 = 0.03365384615384615
0.03365384615384615 x 100 = 3.37%