-3.19% is the change from 878 to 850
Calculation steps:
[( 850 - 878 ) ÷ 878] x 100 = -3.19%
Formula
Percentage change = [(850 - 878) / 878] x 100
Subtract the new number by the original number
850 - 878 = -28
-28 ÷ 878 = -0.03189066059225513
-0.03189066059225513 x 100 = -3.19%