I want to create a graph chart which shows the amount of new debtors per month.
I'm using logfiles as data and these logfiles are created each day. Every day is a new logfile.
The problem I'm running into is that I want to count each debtor only the first time they got logged.
I can't use a distinct count, because if I show the amount of debtors per month, then the debtors who were
online in february and march are counted as 1 in both months. I want it that when someone's first logged event is february, then the only month that debtor is counted in is february. If he is also online in march, he shouldnt be counted.