-13.51% is the change from 770 to 666
Calculation steps:
[( 666 - 770 ) ÷ 770] x 100 = -13.51%
Formula
Percentage change = [(666 - 770) / 770] x 100
Subtract the new number by the original number
666 - 770 = -104
-104 ÷ 770 = -0.13506493506493505
-0.13506493506493505 x 100 = -13.51%