-6.5% is the change from 939 to 878
Calculation steps:
[( 878 - 939 ) ÷ 939] x 100 = -6.5%
Formula
Percentage change = [(878 - 939) / 939] x 100
Subtract the new number by the original number
878 - 939 = -61
-61 ÷ 939 = -0.06496272630457935
-0.06496272630457935 x 100 = -6.5%