-68.13% is the change from 320 to 102
Calculation steps:
[( 102 - 320 ) ÷ 320] x 100 = -68.13%
Formula
Percentage change = [(102 - 320) / 320] x 100
Subtract the new number by the original number
102 - 320 = -218
-218 ÷ 320 = -0.68125
-0.68125 x 100 = -68.13%