DLM cloud watch matrics

Hi All, I have setup the DLM for daily & weekly backup of EBS volumes. I have setup the cloud matrics to get the total count of the Snapshot completed & failed. The sum of data is based on the period filter not the duration i.e.,

1. If the period =1day and Duration : 1 months, it shows sum= 1
2. If the period=7days and Duration : 1 Months, it shows sum = 7
3. If the period=30days and Duration : 1 Months, it shows sum = 30

I want that when I select the duration, it should show total count of completed & failed snapshot. Please suggest.

Regards, Nikhil Shah