-23.79% is the change from 870 to 663
Calculation steps:
[( 663 - 870 ) ÷ 870] x 100 = -23.79%
Formula
Percentage change = [(663 - 870) / 870] x 100
Subtract the new number by the original number
663 - 870 = -207
-207 ÷ 870 = -0.23793103448275862
-0.23793103448275862 x 100 = -23.79%