-96.75% is the change from 400 to 13
Calculation steps:
[( 13 - 400 ) ÷ 400] x 100 = -96.75%
Formula
Percentage change = [(13 - 400) / 400] x 100
Subtract the new number by the original number
13 - 400 = -387
-387 ÷ 400 = -0.9675
-0.9675 x 100 = -96.75%