-80.92% is the change from 870 to 166
Calculation steps:
[( 166 - 870 ) ÷ 870] x 100 = -80.92%
Formula
Percentage change = [(166 - 870) / 870] x 100
Subtract the new number by the original number
166 - 870 = -704
-704 ÷ 870 = -0.8091954022988506
-0.8091954022988506 x 100 = -80.92%