help with time concurrent variable

[dtrobert]

 Hi,

 I'm trying to plot the number of records that are concurrent from a table which has

 ID, starttime, endtime

 

In other words, let's say I have

ID   starttime    endtime

1    11:00          11:03

2    11:01          11:05

3:   11:02          11:03

4:   11:04         11:07

 

and want the concurrency at a minute interval.  I would get 

time     numberOfConcurrent

11:00    1

11:01    2

11:03   2

11:04   2

 

Does anyone know how I can do this in jasper reports, maybe with a variable and reset group where my group is like minutes?

 

Thanks