-75.86% is the change from 870 to 210
Calculation steps:
[( 210 - 870 ) ÷ 870] x 100 = -75.86%
Formula
Percentage change = [(210 - 870) / 870] x 100
Subtract the new number by the original number
210 - 870 = -660
-660 ÷ 870 = -0.7586206896551724
-0.7586206896551724 x 100 = -75.86%