3.55% is the change from 620 to 642
Calculation steps:
[( 642 - 620 ) ÷ 620] x 100 = 3.55%
Formula
Percentage change = [(642 - 620) / 620] x 100
Subtract the new number by the original number
642 - 620 = 22
22 ÷ 620 = 0.035483870967741936
0.035483870967741936 x 100 = 3.55%