-17.68% is the change from 809 to 666
Calculation steps:
[( 666 - 809 ) ÷ 809] x 100 = -17.68%
Formula
Percentage change = [(666 - 809) / 809] x 100
Subtract the new number by the original number
666 - 809 = -143
-143 ÷ 809 = -0.17676143386897405
-0.17676143386897405 x 100 = -17.68%