-77.81% is the change from 320 to 71
Calculation steps:
[( 71 - 320 ) ÷ 320] x 100 = -77.81%
Formula
Percentage change = [(71 - 320) / 320] x 100
Subtract the new number by the original number
71 - 320 = -249
-249 ÷ 320 = -0.778125
-0.778125 x 100 = -77.81%