-20.25% is the change from 400 to 319
Calculation steps:
[( 319 - 400 ) ÷ 400] x 100 = -20.25%
Formula
Percentage change = [(319 - 400) / 400] x 100
Subtract the new number by the original number
319 - 400 = -81
-81 ÷ 400 = -0.2025
-0.2025 x 100 = -20.25%