-75.9% is the change from 668 to 161
Calculation steps:
[( 161 - 668 ) ÷ 668] x 100 = -75.9%
Formula
Percentage change = [(161 - 668) / 668] x 100
Subtract the new number by the original number
161 - 668 = -507
-507 ÷ 668 = -0.7589820359281437
-0.7589820359281437 x 100 = -75.9%