-29.07% is the change from 939 to 666
Calculation steps:
[( 666 - 939 ) ÷ 939] x 100 = -29.07%
Formula
Percentage change = [(666 - 939) / 939] x 100
Subtract the new number by the original number
666 - 939 = -273
-273 ÷ 939 = -0.29073482428115016
-0.29073482428115016 x 100 = -29.07%