Custom Report

Hello,

I've created a report :

       client   client   client

date ...       ...        ...

date ...       ...        ...

date ...       ...        ...

with custom report/historical. But there is too many client.

Can you explain me, how can i do a report :

        date    date    date

client ...       ...        ...

client ...       ...        ...

client ...       ...        ...

?

Thanks