Disk I/O data collection

Hi

I am using OpManager and have added the following monitors:

IO Batch Writes
IO Outstanding Reads
IO Outstanding Writes
IO Page Reads

I have specified the threshold and rearm alerts and the monitors do show "normal"
However when I click on the monitor to view a report it shows "no data available"

How can I generate a report on the IO data? so i can work out the averages over a week?

Thanks
Joe