Fall I 2010

Fall II 2010

Spring I 2010

Spring II 2011

Summer 2011

Fall I 2011

I have no trouble writing a query in order to collect all of the data by session and then of course grouping it by say website or market and I even know how to write a query to create a formula such as "clicks/impressions" = CTR.  It's all great.  

EXCEPT....I want to be able to group the first five listed above to give myself totals and to give myself an accurate CTR.  I know this sounds slightly confusing, BUT...in order to get an accurate CTR I have to take TOTAL CLICKS / TOTAL IMPRESSIONS.  Which is easy if I eliminate the "Session" field from the query.  My problem is that I want to get one chart that totals up the clicks for the first five sessions and divides it by the total impressions for the first five sessions.  Then I want another chart that takes the 6th session and gives me the total clicks divided by the total impressions.

Is there a way to do this?  My problem is that if I place the session as a field in the query, and then I try to filter my CTR is instead a SUM or AVE of the five CTR's (each session).  

I didn't know if it was possible to write a Query that "excludes" any session values.  Ideally I could create a SQL query that doesn't place "session" as a field, but instead I could write the query to not calculate the information in any rows with a particular "session" in them.

Any help you can offer would be greatly appreciated.

Thanks,

Jamie