-1.38% is the change from 870 to 858
Calculation steps:
[( 858 - 870 ) ÷ 870] x 100 = -1.38%
Formula
Percentage change = [(858 - 870) / 870] x 100
Subtract the new number by the original number
858 - 870 = -12
-12 ÷ 870 = -0.013793103448275862
-0.013793103448275862 x 100 = -1.38%