50.15% is the change from 339 to 509
Calculation steps:
[( 509 - 339 ) ÷ 339] x 100 = 50.15%
Formula
Percentage change = [(509 - 339) / 339] x 100
Subtract the new number by the original number
509 - 339 = 170
170 ÷ 339 = 0.5014749262536873
0.5014749262536873 x 100 = 50.15%