-74.32% is the change from 666 to 171
Calculation steps:
[( 171 - 666 ) ÷ 666] x 100 = -74.32%
Formula
Percentage change = [(171 - 666) / 666] x 100
Subtract the new number by the original number
171 - 666 = -495
-495 ÷ 666 = -0.7432432432432432
-0.7432432432432432 x 100 = -74.32%