-2.5% is the change from 879 to 857
Calculation steps:
[( 857 - 879 ) ÷ 879] x 100 = -2.5%
Formula
Percentage change = [(857 - 879) / 879] x 100
Subtract the new number by the original number
857 - 879 = -22
-22 ÷ 879 = -0.02502844141069397
-0.02502844141069397 x 100 = -2.5%