Time is calculating even after logging out

Summary

Time is calculating even after logging out

Content

Hi 

I copied the standard report "Incident web visit" and changed the filter to contact.ID and placed in contact workspace. Actually it has to calculate the time spent by customer on each page in customer portal.It is calculating the time but the problem is that it is calculating the time for the last page the customer visited even after he logged out until he logs in again. Is this the behaviour or can we restrict the time calculation after the customer logs out ?

Refer the attachment, for the page "UnderstandYourInvoice" it is showing 699 hrs.