-78.75% is the change from 320 to 68
Calculation steps:
[( 68 - 320 ) ÷ 320] x 100 = -78.75%
Formula
Percentage change = [(68 - 320) / 320] x 100
Subtract the new number by the original number
68 - 320 = -252
-252 ÷ 320 = -0.7875
-0.7875 x 100 = -78.75%