Summary statistics for a point in time?

Hello,

I'm trying to create graphs and summary statistics (the text at the  
top with max, avg, and cur values) for a point in time in the past.   
I know how to create the graph, and I'm trying to find out if it's  
possible to create the summary statistics using the same time  
segment.  It always seems to give me the current values.  Does  
anybody know how to do this?

Thanks,

Michael Grinnell
Network Security Administrator
The American University