-2.77% is the change from 685 to 666
Calculation steps:
[( 666 - 685 ) ÷ 685] x 100 = -2.77%
Formula
Percentage change = [(666 - 685) / 685] x 100
Subtract the new number by the original number
666 - 685 = -19
-19 ÷ 685 = -0.027737226277372264
-0.027737226277372264 x 100 = -2.77%