-12.78% is the change from 939 to 819
Calculation steps:
[( 819 - 939 ) ÷ 939] x 100 = -12.78%
Formula
Percentage change = [(819 - 939) / 939] x 100
Subtract the new number by the original number
819 - 939 = -120
-120 ÷ 939 = -0.12779552715654952
-0.12779552715654952 x 100 = -12.78%