-99.06% is the change from 320 to 3
Calculation steps:
[( 3 - 320 ) ÷ 320] x 100 = -99.06%
Formula
Percentage change = [(3 - 320) / 320] x 100
Subtract the new number by the original number
3 - 320 = -317
-317 ÷ 320 = -0.990625
-0.990625 x 100 = -99.06%