call voulme to one simple extension

[hulk68]

I have one extension I need to get reports for.
It is not in a hunt group or anything else like that, just a stand alone DID extension.
It is a simple extension that only goes to vmail after 3 rings.
I just want to know how many calls go to the extension a month.

I have ASA and a Definity G3si.

Thanks you.