-33.72% is the change from 768 to 509
Calculation steps:
[( 509 - 768 ) ÷ 768] x 100 = -33.72%
Formula
Percentage change = [(509 - 768) / 768] x 100
Subtract the new number by the original number
509 - 768 = -259
-259 ÷ 768 = -0.3372395833333333
-0.3372395833333333 x 100 = -33.72%