Calculate Task Completion and Display the message "Completed".

Above screen shot. Created new column with ..... 

Days Left or OverDue = 'XXX'[Actual Due Date]-TODAY() .....

to calculate the days left or overdue.

But some tasks already completed. Instead of showing days (-100) or (-9) for completed tasks, I want to show up for the completed tasks (Completed), as of completion % showing 100%. 

Also, I want to show up for over due, if tasks not completed within time duration, show up (9 Days Overdue).