-81.61% is the change from 669 to 123
Calculation steps:
[( 123 - 669 ) ÷ 669] x 100 = -81.61%
Formula
Percentage change = [(123 - 669) / 669] x 100
Subtract the new number by the original number
123 - 669 = -546
-546 ÷ 669 = -0.8161434977578476
-0.8161434977578476 x 100 = -81.61%