Add up numbers from last month + current month

[Paladin_Brewer]

Alright, let me see if I can explain this. I have fields for both a Month and a Year for when someone Joins. Lets call them Join_Month and Join_Year fields. I also have a Yes/No boolean field as to whether or not they are active. Lets call it.

I need to do reports that show who is a member for each month. For example, let's say its July and there are 30 members on the report. Now lets say 4 more people join in August. So for the August field in the report, it would show those 4 + the other 30 that have been members already, showing 34 members for August.

On top of that I was wondering if it was possible to automatically generate new months as they come along so the user wouldnt.

Is this possible at all? :

[Paladin_Brewer]

I will give fresh baked cookies for anyone who can help. This is my last major problem to finishing these DB changes for a client, and they need it soon :

[Paladin_Brewer]

Anyone? Am I not explaining it very well, need more details, etc? : I cant seem to find a solution and I need to have this done very soon :