-97.8% is the change from 409 to 9
Calculation steps:
[( 9 - 409 ) ÷ 409] x 100 = -97.8%
Formula
Percentage change = [(9 - 409) / 409] x 100
Subtract the new number by the original number
9 - 409 = -400
-400 ÷ 409 = -0.9779951100244498
-0.9779951100244498 x 100 = -97.8%