Percentage of completion for Activity

Hello,

In the project builder while creating the structure especially for activities i need to view the percentage of completion for each activity. I have already tried to provide the percentage of completion while confirming the activity but once i save the project structure and view the same activity for percentage of completion it by default takes into 100 percent completion with Final Confirmation checked and Completed Checked.

Kindly guide me how to show this info where do i have to correct and take it forward.

Kindly do the needful ASAP.

Regards

Praveen B M