21.33% is the change from 511 to 620
Calculation steps:
[( 620 - 511 ) ÷ 511] x 100 = 21.33%
Formula
Percentage change = [(620 - 511) / 511] x 100
Subtract the new number by the original number
620 - 511 = 109
109 ÷ 511 = 0.21330724070450097
0.21330724070450097 x 100 = 21.33%