-33.64% is the change from 770 to 511
Calculation steps:
[( 511 - 770 ) ÷ 770] x 100 = -33.64%
Formula
Percentage change = [(511 - 770) / 770] x 100
Subtract the new number by the original number
511 - 770 = -259
-259 ÷ 770 = -0.33636363636363636
-0.33636363636363636 x 100 = -33.64%