78.59% is the change from 509 to 909
Calculation steps:
[( 909 - 509 ) ÷ 509] x 100 = 78.59%
Formula
Percentage change = [(909 - 509) / 509] x 100
Subtract the new number by the original number
909 - 509 = 400
400 ÷ 509 = 0.7858546168958742
0.7858546168958742 x 100 = 78.59%