3.51% is the change from 599 to 620
Calculation steps:
[( 620 - 599 ) ÷ 599] x 100 = 3.51%
Formula
Percentage change = [(620 - 599) / 599] x 100
Subtract the new number by the original number
620 - 599 = 21
21 ÷ 599 = 0.035058430717863104
0.035058430717863104 x 100 = 3.51%