-99.55% is the change from 666 to 3
Calculation steps:
[( 3 - 666 ) ÷ 666] x 100 = -99.55%
Formula
Percentage change = [(3 - 666) / 666] x 100
Subtract the new number by the original number
3 - 666 = -663
-663 ÷ 666 = -0.9954954954954955
-0.9954954954954955 x 100 = -99.55%