Please help with a query

From: Al (anonymous_at_discussions.microsoft.com)
Date: 04/29/04 

Date: Thu, 29 Apr 2004 11:50:41 -0700

I need to count the number of patients that have a
StartDate <1/1/02 and StopDate >= 1/1/02. At this point
this is easy. The difficult part is I need to do the same
for every month till 12/31/04, i.e. Total no. of patients
where StartDate <2/1/02 and StopDate >= 2/1/02, . Total
no. of patients where StartDate <3/1/02 and StopDate >=
3/1/02, etc. I need to include all patients that have
StopDate = null, as well, in this count. Is this possible
to do it in one qry. I need this qry to plot a graph that
will show the total number of patients per/month from
start to end. Can someone help?
Thanks
Al