-56.15% is the change from 390 to 171
Calculation steps:
[( 171 - 390 ) ÷ 390] x 100 = -56.15%
Formula
Percentage change = [(171 - 390) / 390] x 100
Subtract the new number by the original number
171 - 390 = -219
-219 ÷ 390 = -0.5615384615384615
-0.5615384615384615 x 100 = -56.15%