20.04% is the change from 509 to 611
Calculation steps:
[( 611 - 509 ) ÷ 509] x 100 = 20.04%
Formula
Percentage change = [(611 - 509) / 509] x 100
Subtract the new number by the original number
611 - 509 = 102
102 ÷ 509 = 0.20039292730844793
0.20039292730844793 x 100 = 20.04%