-80.34% is the change from 870 to 171
Calculation steps:
[( 171 - 870 ) ÷ 870] x 100 = -80.34%
Formula
Percentage change = [(171 - 870) / 870] x 100
Subtract the new number by the original number
171 - 870 = -699
-699 ÷ 870 = -0.803448275862069
-0.803448275862069 x 100 = -80.34%