-4.56% is the change from 921 to 879
Calculation steps:
[( 879 - 921 ) ÷ 921] x 100 = -4.56%
Formula
Percentage change = [(879 - 921) / 921] x 100
Subtract the new number by the original number
879 - 921 = -42
-42 ÷ 921 = -0.04560260586319218
-0.04560260586319218 x 100 = -4.56%