-28.86% is the change from 939 to 668
Calculation steps:
[( 668 - 939 ) ÷ 939] x 100 = -28.86%
Formula
Percentage change = [(668 - 939) / 939] x 100
Subtract the new number by the original number
668 - 939 = -271
-271 ÷ 939 = -0.288604898828541
-0.288604898828541 x 100 = -28.86%