-75% is the change from 664 to 166
Calculation steps:
[( 166 - 664 ) ÷ 664] x 100 = -75%
Formula
Percentage change = [(166 - 664) / 664] x 100
Subtract the new number by the original number
166 - 664 = -498
-498 ÷ 664 = -0.75
-0.75 x 100 = -75%
Example