-6.39% is the change from 939 to 879
Calculation steps:
[( 879 - 939 ) ÷ 939] x 100 = -6.39%
Formula
Percentage change = [(879 - 939) / 939] x 100
Subtract the new number by the original number
879 - 939 = -60
-60 ÷ 939 = -0.06389776357827476
-0.06389776357827476 x 100 = -6.39%