Call statistics can fall into the three following categories. i) Succesfull calls ii) No dialling cases (Subscriber lifts the handset but keeps it down after getting the dialtone. iii) Incomplete dialling cases.
For the 2nd and 3rd cases, usually no system will maintain the statistics with respect to the subscriber. It is stored only for the traffic analysis of the entire system. This information can tell us the number of callers trying to enter into the system, but it doesn’t really tell us which caller was trying and how many times for the cases 2 & 3.
As far as the switch is concerned, it doesn’t make any difference whether one person is trying to call 400 times or 400 persons trying once.