-89.34% is the change from 666 to 71
Calculation steps:
[( 71 - 666 ) ÷ 666] x 100 = -89.34%
Formula
Percentage change = [(71 - 666) / 666] x 100
Subtract the new number by the original number
71 - 666 = -595
-595 ÷ 666 = -0.8933933933933934
-0.8933933933933934 x 100 = -89.34%