68.37% is the change from 509 to 857
Calculation steps:
[( 857 - 509 ) ÷ 509] x 100 = 68.37%
Formula
Percentage change = [(857 - 509) / 509] x 100
Subtract the new number by the original number
857 - 509 = 348
348 ÷ 509 = 0.6836935166994106
0.6836935166994106 x 100 = 68.37%