[SQL] how many times

I am not for sure how to do the below.  I was hoping someone could share their thoughts.

Assume I have a table called T1.  It contains a single filed called “viewed” that is of type timestamp.

Every time someone views a particular web page we insert the current timestamp into T1.

Now I need to ask this business question:

On average in any consecutive five minute time frame how many times is the web page viewed?

Thanks,

Lance