-74.1% is the change from 641 to 166
Calculation steps:
[( 166 - 641 ) ÷ 641] x 100 = -74.1%
Formula
Percentage change = [(166 - 641) / 641] x 100
Subtract the new number by the original number
166 - 641 = -475
-475 ÷ 641 = -0.7410296411856474
-0.7410296411856474 x 100 = -74.1%