31.24% is the change from 509 to 668
Calculation steps:
[( 668 - 509 ) ÷ 509] x 100 = 31.24%
Formula
Percentage change = [(668 - 509) / 509] x 100
Subtract the new number by the original number
668 - 509 = 159
159 ÷ 509 = 0.31237721021611004
0.31237721021611004 x 100 = 31.24%